Isao Fujimori

Interaction between Oral Alpha-Streptococci and Group a Streptococci in Patients with Tonsillitis

The incidence of oral α-streptococci with inhibitory activity against group A streptococci, as a defense mechanism against bacterial infection in the oral cavity, was investigated in 141 patients with streptococcal tonsillitis. The study population included both children (n = 79) and adults (n = 62). Infection by group A streptococci appeared to be more common in children than in adults, as the detection rates of inhibitory α-streptococci in healthy children (29.7%), as well as pediatric patients with tonsillitis (14.9%), were lower than those in adults (63.0%; p < .01). It is possible to consider oral α-streptococci with inhibitory activity to be among the indications for tonsillectomy in patients with streptococcal tonsillitis, since the detection rate of inhibitory α-streptococci in surgical cases (10.9%) was significantly lower than that in nonsurgical cases (31.1 %; p < .01). The high detection rate of these strains during the postoperative state supported the observation that the incidence of group A streptococcal infection was decreased postoperatively. Accordingly, it is useful to investigate bacterial interference between oral α-streptococci and group A streptococci in patients scheduled for tonsillectomy.

Investigation of oral α-streptococcus showing inhibitory activity against pathogens in children with tonsillitis

The incidence of oral alpha-streptococcus with inhibitory activity against group A streptococcus, as a defense mechanism against bacterial infection in the oral cavity, was investigated in pediatric individuals with tonsillitis. Infection by group A streptococcus appeared to be common in children, because the detection rate of inhibitory alpha-streptococcus in healthy children as well as pediatric patients with tonsillitis was lower than in adults and elderly patients. In particular, the detection rate of these strains was predominantly low in patients with beta-streptococcus. Among pediatric patients scheduled for tonsillectomy, the detection rate of inhibitory alpha-streptococcus was low preoperatively. However, the rate was markedly increased after surgery. The high postoperative detection rate of these strains reflected the decreased incidence of group A streptococcal infection. The results of this investigation of bacterial interference between oral alpha-streptococcus and group A streptococcus suggested that surgical treatment is a more effective approach for improving the oral bacterial flora in children with recurrent tonsillitis.

Age‐related Alterations in the Auditory Brainstem Responses and the Compound Action Potentials in Guinea Pigs

The auditory brainstem response (ABR) and the eighth nerve compound action potential (CAP) were measured using click stimuli to investigate the agerelated alteration in the auditory function in 66 guinea pigs consisting of four age groups. With advancing age, a gradual elevation of the thresholds in both the ABR and CAP was clearly seen, together with the prolonged latencies for waves I, II, III, and IV to clicks at 95 dBpeSPL in the ABR. There were some individual differences in either threshold elevation or latency prolongation of both the ABR and CAP in aged guinea pigs. These findings suggest that the effect of individual differences on degenerative aging processes of the auditory system should be considered in selected aged animals, although a significant elevation of the neural auditory threshold is clearly found with advancing age as a whole.

Study on Orthostatic Dysregulation and the Schellong Test in Healthy Young Females

We carried out a questionnaire survey regarding the symptoms of orthostatic dysregulation (OD) and administered the Schellong test to 301 healthy young females ranging in age from 18 to 21 years. OD was identified in 62 (20.6%) of the subjects based on the questionnaire. Although orthostatic dizziness was relatively common in the entire group of young females (171/301, 56.8%), this symptom was much more prevalent in the subjects with OD (58/62, 93.5%). There was also a highly significant difference between the systolic pressure decrease during the Schellong test procedure in 22 subjects with OD with frequent orthostatic dizziness and that in the 239 subjects without OD. Although the clinical value of the Schellong test in the assessment of OD and other related conditions has been brought into question because of its relatively poor specificity, we conclude that this test procedure may be useful in screening for OD or autonomic nerve dysfunction, since it presents the advantage of easy application in clinical practice.

病原菌発育抑制性α-レンサ球菌の口腔内定着状況と喫煙, 含嗽の及ぼす口腔細菌叢への影響について

We investigated the distribution of oral alpha-streptococci with inhibitory activity against pathogens, which compose an oral defense mechanism. Detection rate of alpha-streptococci with inhibitory activity against S. pyogenes and S. aureus derived from the tonsil was higher than in other portions, the tongue, cheek, gingiva, or saliva. It has suggested that tonsillar bacterial flora are mainly a defense mechanism. The oral flora in healthy smokers was compared with healthy non-smokers to investigate the influence of tobacco on oral bacterial flora. The results showed that the detection rate of S. aureus in smokers was higher while that of alpha-streptococci with inhibitory activity against S. aureus was lower. However, the detection rate of alpha-streptococci with inhibitory activity against S. pyogenes in smokers was as high as in non-smokers. It is suggested that it was easy for S. aureus to adhere to the oral mucosa in smokers, and was considered to influence the strain which produces beta-lactamase for medical treatment. We investigated the influence of gargling on oral bacterial flora by comparing the amount of bacteria before and after gargling with popidine-iodine gargle and saline solution. It was shown that alpha-streptococci, a main component of normal oral flora were decreased after gargling in both smokers and non-smokers. Furthermore, it was shown that group A Streptococcus was not decreased after gargling, and it was concluded that use of gargle medicinal mouth wash in bacillus carriers should be studied further.

Investigation of the nasopharyngeal bacterial flora in children with otitis media with effusion.

A study was undertaken to evaluate the incidence of alpha-streptococci with inhibitory activity against pathogens, a defense mechanism of the normal flora against bacterial infection, in the nasopharynx and tonsils of 37 children with otitis media with effusion (OME). In the patients with OME, the detection rates of alpha-streptococci with inhibitory activity against Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus and group A streptococci in the nasopharynx were significantly lower than those of alpha-streptococci isolated from the tonsils. Furthermore, the detection rates of nasopharyngeal alpha-streptococci with inhibitory activity against H. influenzae and S. pneumoniae in OME patients were lower than those in patients with tonsillitis. In conclusion, low nasopharyngeal levels of alpha-streptococci with inhibitory activity against pathogens appear to render children susceptible to attacks of OME. We suggest that it is important to investigate the relationships between the prevalence of pathogens and the inhibitory activity of alpha-streptococci against them in the nasopharynx.

Analysis of defense mechanisms against bacterial infection by oral streptococcus in normal flora

The incidence of oral alpha-streptococci with inhibitory activity against pathogens as a defense mechanism in the oral cavity was investigated in healthy individuals. Inhibitory strains were isolated from tonsil, tongue, cheek, saliva and dental plaque, and the detection rate of these strains isolated from tonsil was the highest. These results suggested that tonsillar flora is most important as a defense mechanism of the oral cavity. With respect to the effects of antibiotics against inhibitory alpha-streptococci, minimal inhibitory concentration of 90% of cells (MIC90) of PCG, ABPC, CCL, CFIX and EM against inhibitory alpha-streptococci, and relative detection rates of inhibitory alpha-streptococci before and after antimicrobial therapy were investigated. MIC90s of all antibiotics against these strains were low and sensitive to antibiotics tested. However, in vivo, detection rates of these strains before and after therapy did not differ significantly. Therefore, inhibitory strains were not affected by antibiotics as their MIC90 were low during short term medication.

[Participation in causing O.M.E. with nasopharyngeal alpha-Streptococcus].

The role of normal pharyngeal flora in the defense mechanism against infections in the upper respiratory tract was studied in 50 children with otitis media with effusion (O.M.E.). In the bacteriological study of the nasopharynx, the incidence of H. influenzae, S. pneumoniae, S. aureus, M. catarrhalis and group A Streptococcus was about 46%, 24%, 20%, 12% and 8%, respectively. The incidence of these species in the cases with O.M.E. was higher than that in the cases with chronic tonsilitis or control cases. In 41 O.M.E. cases with alpha-streptococci (82%), the incidence of alpha-streptococci with inhibitory activity against 5 pathogens (H. influenzae, S. pneumoniae, S. aureus, M. catarrhalis, group A Streptococcus) was examined. The detection rate of alpha-streptococcal strains with inhibitory activity against 5 pathogens derived from the nasopharynx in the cases with O.M.E. was significantly lower than that of the strain in the chronic tonsilitis cases and the control cases. Moreover, the detection rate of inhibitory alpha-streptococci from the nasopharynx was lower than that of from the tonsil. These findings suggest that the decline of inhibitory activity against pathogens by normal flora in nasopharynx is one of the factors causing O.M.E.