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Biomedical subjects

N Rikitomi

Publications and source records attributed to N Rikitomi.

52 records · Page 3Linked to original sources
PubMed1989

In vitro adherence of Streptococcus pneumoniae to oropharyngeal cells: enhanced activity and colonization of the upper respiratory tract in patients with recurrent respiratory infections.

In vitro adherence of Streptococcus pneumoniae (S. pneumoniae) to oropharyngeal cells was assessed in 3 age matched groups of 29 subjects. The first group included patients with chronic pulmonary disease and recurrent respiratory infections due to S. pneumoniae or a recent respiratory infection caused by this organism. Patients of the second group has similar underlying pulmonary disease to the first group, but they had no S. pneumoniae respiratory infection for at least the past 3 years. Healthy subjects or patients without underlying pulmonary disease constituted the third group. The mean adherence of S. pneumoniae to oropharyngeal cells was 10.6 +/- 4.7 bacteria (bact.)/cell in the first group, 3.6 +/- 2.8 bact./cell in the second group and 1.9 +/- 2.1 bact./cell in the third group. A significant difference was found (p less than 0.01) when the mean of the first group was compared to those of the second and third groups, whereas there was no significant difference between the means of the second and third groups. In addition, a survey of bacterial colonization of the upper respiratory tract was conducted in all the subjects included in this study. Over 6 months, 5 of the 8 patients in the first group had throat cultures (5 cases) and nasal cultures (3 cases) positive for S. pneumoniae, while no one in the second or third group was a carrier of this bacterium in the upper respiratory tract during the same period. Patients with recurrent or recent respiratory infections caused by S. pneumoniae are characterised by an in vitro enhanced ability of this organism to adhere to their oropharyngeal cells. In vivo, this phenomenon is reflected by an increased susceptibility of the upper respiratory tract to colonization by S. pneumoniae.

Adult↗
PubMed1987

Correlation between Branhamella catarrhalis adherence to oropharyngeal cells and seasonal incidence of lower respiratory tract infections.

Bacterial colonization of the oropharynx is the initial event in most lower respiratory tract infections. To study the role of bacterial adherence in lower respiratory tract infections caused by Branhamella catarrhalis (B. catarrhalis) in winter, in vitro adherence assays of the organism to human oropharyngeal cells were carried out in winter, spring, summer and autumn. A total of 57 adults of both sexes were studied from January to December 1985. Forty eight persons of 57 had chronic pulmonary diseases and the remaining 9 persons had other clinical entities and served as the control group. Predominance of lower respiratory tract infections caused by B. catarrhalis with high adherence rate was observed in winter. Adherence activity was moderate in spring and autumn and low in summer and accompanied by a similar incidence of lower respiratory tract infections with this bacteria. In addition, similar results were found in patients in whom investigations were done successively in the above four seasons. Bacterial adherence activity to cells however, was weak in winter in the control group. These results indicate that seasonal variation plays a significant role in the ability of B. catarrhalis to adhere to oropharyngeal cells. This is an important pathogenic factor correlated with the incidence of lower-respiratory tract infections in these patients.

Adult↗
PubMed1987

Lower respiratory tract infections due to non-diphtheria corynebacteria in 8 patients with underlying lung diseases.

Non-Diphtheria corynebacteria had been considered a commensal habitant of the human skin and mucous membrane. There are few reports of pulmonary infections due to Corynebacterium pseudodiphtheriticum or other non-diphtheria corynebacteria occurring in immunocompetent patients. From 1978 to 1986, 8 patients with lower respiratory tract infections with Corynebacterium sp. was observed. In 6 of 8 instances the causative microorganism was C. pseudodiphtheriticum. The above 8 patients had underlying pulmonary diseases but were not associated with immunosuppressive state, except one. Seven of them recovered from the infection in response to antimicrobial therapy. All 6 isolates of C. pseudodiphtheriticum were sensitive to nine antimicrobial agents which were six beta-lactam agents, gentamicin, minocycline and norfloxacin.

Adult↗
PubMed1983

Laboratory evaluation of cefmenoxime: a new cephalosporin. In vitro and in vivo antibacterial activities and pharmacokinetic properties.

Cefmenoxime is a new syn-methoxyimino cephalosporin antibiotic derived from cefotiam, which has been proved to be a very effective and useful antibiotic for the treatment of respiratory infections. This bacteriological and pharmacokinetic study was therefore performed in order to evaluate the potency of cefmenoxime in the treatment of respiratory infections. The minimum inhibitory concentrations of cefmenoxime against 179 isolates of respiratory pathogens (Streptococcus pneumoniae 53, Haemophilus influenzae 64, Klebsiella pneumoniae 43, Escherichia coli 9, Enterobacter spp. 10) were less than 0.20 micrograms/ml, and 43 (73%) of 60 Pseudomonas aeruginosa were inhibited by 12.5 micrograms/ml. In vitro antibacterial activity of cefmenoxime was superior to 18 other antibiotics, including cefotiam and cefotaxime tested in this study. Pharmacokinetic studies on tissue distribution in rats, serum levels and urinary excretion in 3 healthy volunteers, and penetration into bronchial secretes of 9 patients with respiratory infections, revealed that cefmenoxime has a higher penetration into the lung and bronchial secretes compared with cefotiam and cefotaxime. In 1 patient with chronic bronchiolitis, the concentration of cefmenoxime in the intra-bronchial secrete reached 12.5 micrograms/ml. From these results, it is concluded that cefmenoxime is a highly potent and useful antibiotic, and may be more effective in the treatment of respiratory infections than many other cephalosporins, including cefazolin, cefotiam and cefotaxime.

Animals↗