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Biomedical subjects

T Nagatake

Publications and source records attributed to T Nagatake.

At least 127 records · Page 7Linked to original sources

Electron microscopic observation of Branhamella catarrhalis.

The hemagglutination (HA) test was done on 85 strains of Branhamella catarrhalis, isolated from sputum of patients with respiratory infections; 53% were HA positive strains. Three HA positive and three HA negative strains were selected and were observed under the electron microscope. The bacterial cell wall appeared to be lobulated and its total thickness was about 38 nm. The nuclear region consisted of whorls or fibrils and dense bodies. Five strains were fimbriated and one strain was nonfimbriated. The size of fimbriae was about 68 nm in length and 4.5 nm in width. The fimbriae of Branhamella catarrhalis were densely arranged and peritrichous in distribution. There was no change of fimbriation between broth and agar cultures.

Bacterial Infections↗

Application of mathematical model to experimental chemotherapy of fatal murine pneumonia.

Two beta-lactam antibiotics, cefazolin and cefmenoxime, were administered in an experimental model of murine pneumonia caused by Klebsiella pneumoniae in a way which enabled us to approximate the serum antibiotic concentration time course in humans. Bacterial counts during the experiments were subjected to nonlinear least-squares analyses by using a mathematical model that explained the bacterial killing by the antibiotic concentration time course and other factors associated with antimicrobial potency and bacterial growth. Cefazolin gave a killing curve that changed synchronously with the drug levels in serum; in contrast, cefmenoxime gave a curve that was prolonged as compared with the change in the drug levels in serum. Multiple correlation coefficients were about 0.9, and the model worked well for bacterial count data. Parameters relating to antimicrobial potency of the drugs, bacterial growth rate, and drug distribution into the tissue were estimated numerically.

Animals↗

Effect of ampicillin, cefmetazole and minocycline on the adherence of Branhamella catarrhalis to pharyngeal epithelial cells.

Using pharyngeal epithelial cells from a healthy adult and eight strains of Branhamella catarrhalis (B. catarrhalis) isolated from eight patients with respiratory infection the effect of subminimal inhibitory concentrations of cefmetazole, ampicillin and minocycline on adherence was examined. Cefmetazole-treated bacterial attachment (44 +/- 28; mean +/- S.D.) decreased significantly (p less than 0.05) compared to the control (84 +/- 27). Statistically no significant difference in adherence was found between ampicillin-treated bacteria (63 +/- 36) and the control (95 +/- 40) or minocycline-treated bacteria (91 +/- 39) and the control (109 +/- 40). Large bacteria was observed after cefmetazole and ampicillin treatment. In addition to diplococci, tetrads were observed after cefmetazole treatment. Significant correlation between the MICs and adherence ability was not found. The results suggests that these three antibiotics were not responsible for the increase in B. catarrhalis infection by increasing adherence ability.

Ampicillin↗

[Tuberculosis sequelae: secondary bacterial infections].

Bacterial infections is one of the most important complications in the patients with pulmonary tuberculosis. We reported the causative microorganisms in these cases with special reference to various clinical features and presented the recommended treatment and prophylaxis against respiratory bacterial infections in the patients with pulmonary tuberculosis sequelae. In 1988 and 1989, 63 patients with tuberculosis sequela were demonstrated to have been infected with respiratory pathogenic bacteria by the quantitative sputum culture method (greater than or equal to 10(7)/ml) in Tokyo National Chest Hospital. The male/female ratio of these patients was 3.5, and their average age was 62.5 years. Causative microorganisms of the secondary infections in the patients with tuberculosis sequela were essentially similar in those with other lower respiratory tract infections, i.e., chronic bronchitis, bronchiectasis, diffuse panbonchiolitis, chronic pulmonary emphysema, etc. Pseudomonas aeruginosa, other glucose-nonfermentative Gram-negative bacilli (GNF-GNB), and glucose-fermentative Gram-negative bacilli (GF-GNB) were the major pathogenic bacteria responsible for the chronic respiratory failure and/or fatal outcome in the post-tuberculous patients. Patients with complications, including aspergillosis, atypical mycobacteriosis, bronchial asthma, and so forth, showed no specific causative microorganism for the secondary infections except frequent isolation of Haemophilus influenzae. Our clinical observations clearly demonstrated that there were differences between the causative microorganisms in patients hospitalized during 1988 to 1989 and those in patients without admission. Gram-negative bacilli, including P. aeruginosa, GNF-GNB and GF-GNB, and Staphylococcus aureus were predominant in hospitalized patients. On the contrary, Streptococcus pneumoniae, H. influenzae, and Branhamella catarrhalis were major pathogenic bacteria in patients without hospitalization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Respiratory infections caused by Branhamella catarrhalis in 5 different hospitals].

During 9 months (from January 1988 to September 1988), we experienced 82 patients (94 episodes) of respiratory infections with Branhamella catarrhalis in 5 different hospitals. There were 11 patients of acute bronchitis, 8 patients of pneumonia, 56 patients of chronic bronchitis (68 episodes), 3 patients of bronchiectasis, 3 patients of bronchial asthma with infection and chronic pulmonary emphysema in one patient. Ten cases of acute bronchitis and 3 cases of pneumonia had a recent history of common cold, with no underlying disease. There were 68 episodes of acute exacerbation of chronic bronchitis, the highest among 94 episodes of all respiratory infection. In chronic bronchitis the single pathogen B. catarrhalis was more than B. catarrhalis associated with other pathogens. H. influenza was associated with B. catarrhalis in in most cases of polymicrobial infection. beta-lactamase producing B. catarrhalis was 71% and oral penicillin was not effective in 8 cases of infection by beta-lactamase producing strains. These results show that B. catarrhalis is very important as a common pathogen of respiratory infection.

Adult↗

[The antimicrobial activity of fluoroquinolone agents against pathogenic organisms in respiratory tract infections and its clinical effect].

The efficacy rate, minimal inhibitory concentrations (MICs), and resistance of fluoroquinolone agents against causative organisms in respiratory tract infections from January to March, 1988 were investigated. Of 333 pathogenic strains 85% consisted of 5 major causative organisms of respiratory tract infection (Haemophilus influenzae, Pseudomonas aeruginosa, Streptococcus pneumoniae, Branhamella catarrhalis, and Staphylococcus aureus). In 61 (59 cases) of these 333 strains, including 3 cases of acute pharyngitis, 5 of acute bronchitis, 3 of pneumonia, and 48 of chronic lower respiratory tract infection fluoroquinolone agents were administered. The efficacy rate was 76.3% in all cases, and 75% in cases with chronic lower respiratory tract infection. The fluoroquinolone agents were 100% effective in H. influenzae and B. catarrhalis, though the efficacy rate was 67% in S. aureus and 40% in P. aeruginosa. The susceptibility of all strains to fluoroquinolone agents were investigated. There was no resistant strain in H. influenzae and B. catarrhalis, though resistant strains to fluoroquinolone agents have increased in S. aureus and P. aeruginosa. The efficacy rate was investigated using the MIC of administered fluoroquinolone agent against causative organisms. It is surmised that the efficacy of that agent has an MIC of 1.56-3.13 micrograms/ml.

Anti-Bacterial Agents↗

[Therapy of chronic recurrent respiratory tract infections].

In 1987, the most frequently identified pathogens in chronic respiratory tract infections in our clinic were Haemophilus influenzae, Pseudomonas aeruginosa, Branhamella catarrhalis, Streptococcus pneumoniae, Staphylococcus aureus and Klebsiella pneumoniae. Recurrent infection is a common phenomenon in patients with chronic respiratory tract infections, including chronic bronchitis, chronic bronchiolitis and bronchiectasis. H. influenzae is the most common pathogen in such patients. Macrolides, tetracyclines and new quinolones were effective to protect against recurrent infection of H. influenzae and these finding suggested that L-forms of H. influenzae may be significant in the recurrence of infection in patients with chronic respiratory tract infection. Bacterial colonization of the oropharynx is the initial event in most lower respiratory tract infections. Gargling protects against bacteria colonization of the oropharynx and occurrence of acute exacerbation.

Anti-Bacterial Agents↗

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↗

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↗