Takayuki Masutani

γ Heavy chain disease screening showing a discrepancy between electrophoretic and nephelometric determinations of serum γ globulin concentration

A 75-year-old woman with rheumatoid arthritis showed a discrepancy between the reduced level of serum γ globulin on cellulose acetate electrophoresis and the normal level of serum IgG determined by laser nephelometry. Although no M-peak was detectable on cellulose acetate electrophoresis, immunoelectrophoresis of the patients serum revealed a monoclonal protein reacting with anti-IgG antiserum but not with anti-κ or anti-λ light chain antiserum. Western blotting of the patients serum showed abnormal low-molecular-weight γ chains. Thus, the patient was diagnosed with γ heavy chain disease. A comparison of γ globulin levels determined by different methods may be useful when screening for this disease.

経気管吸引法 (TTA) による嫌気性菌呼吸器感染症の臨床的検討

We evaluated the clinical and bacteriologic features in the patients with bronchopulmonary infections isolated anaerobes from transtracheal aspirates between April 1990 and March 1998. Some anaerobe was isolated in 42 (10.9%) in 387 patients whom we performed transtracheal aspiration (TTA), in 42 (15.7%) of 268 in whom some organism was isolated from TTA, or in 42 (16.3%) of 257 patients in whom some bacterium excluding acid-fast bacteria, fungi or mycoplasma from TTA. The isolation rate of anaerobic bacteria was 93.3% in the patients with lung abscess, 22.7% in the patients with nosocomial pneumonia, 19.4% in the patients with community-acquired pneumonia, 26.7% in the patients with acute exacerbation of chronic lower respiratory tract infection (CLRTI), 1.6% in the patients with persistent infection of CLRTI, and 3.0% in the patients with acute bronchitis, respectively. The major anaerobes, isolated from TTA, were Peptostreptococcus micros and Prevotella melaninogenica. The aerobic bacteria were isolated with anaerobic bacteria in 32 of 42 patients at the same time. The quantitive grade of colonial growth of anaerobes was equal to or more than aerobes in the patients with lung abscess and pneumonia. We mostly administrated 3rd generation cephems or carbapenems with or without clindamycin for the treatment of anaerobic infections. Forty-one of 42 patients were cured only by the therapy of antimicrobial agents, but pneumonia patient with lung cancer died in spite of adequate antimicrobial therapy. These results suggest that the anaerobic infections are important in the bronchopulmonary infections.

経気管吸引法 (TTA) にてムコイド型緑膿菌を検出した呼吸器感染症の臨床的検討

We performed a clinical study of 20 cases (33 episodes) of respiratory infections due to mucoid Pseudomonas aeruginosa by transtracheal aspiration (TTA) in the recent 10 years. There was only one pneumonia without underlying chronic lower respiratory infection (CLRTI) case positive for mucoid P. aeruginosa and others were all CLRTI among 33 TTA trials. In contrast, nonmucoid P. aeruginosa was recovered from 9 cases of respiratory infections without underlying CLRTI among 46 TTA trials. Monomicrobial infection of mucoid P. aeruginosa was 69.7%, and polymicrobial infection containing mucoid P. aeruginosa was 30.3%, and Haemophilus influenzae was the most frequent microorganism recovered with mucoid P. aeruginosa. The recovery rate of mucoid P. aeruginosa among P. aeruginosa-colonized cases was 56.3% in diffuse panbronchiolitis, and that was 42.9% and 40.0% in bronchiectasis and chronic bronchitis, respectively. Mortality due to pneumonia with nonmucoid P. aeruginosa was 46.1%, but there was no fatal pneumonia case with mucoid P. aeruginosa. In CLRTI, laboratory data were not remarkably different between mucoid and non-mocoid P. aeruginosa-colonized cases. Thus, these results suggest that mucoid P. aeruginosa is a more important organism in persistent infections in the lower respiratory tract compared with nonmucoid P. aeruginosa, and further investigations is required on the mechanism and clinical role of this infection.

経気管吸引法 (TTA) による呼吸器感染症の病態解析-1, 416例の集計から-

We have performed transtracheal aspiration (TTA) in 1,416 patients, who were suspected to have bronchopulmonary infection, in order to collect non-contaminated specimens directly from the lower airway. The overall isolation rates in 1,416 TTA were 68.7% for any microorganisms. Aerobes had a high incidence but many kinds of microorganisms were associated with bronchopulmonary infections. Haemophilus influenzae was the major pathogen in patients with acute bronchitis. Streptococcus pneumoniae was the most important pathogen and mycoplasma was often isolated in patients with community-acquired pneumonia. Major pathogens of nosocomial pneumonia consisted of alpha-streptococcus spp., anaerobes and Pseudomonas aeruginosa. Anaerobes were isolated from transtracheal aspirates in 20 of 33 episodes of lung abscesses. H. influenzae and P. aeruginosa were the main persistent pathogens and H. influenzae, S. pneumoniae and anaerobes were important exacerbated pathogens in patients with chronic lower respiratory tract infection. S. pneumoniae was isolated more from TTA than expectorated sputa. Oropharyngeal flora bacteria were easily isolated in the culture of expectorated sputa. We assessed the final diagnosis or causative factor in 443 patients whom no microorganism was isolated from transtracheal aspirates. The final diagnosis was infectious diseases in 52 patients (11.7%) and non-infectious diseases in 80 patients (18.1%), respectively. The causative factor was unsuited TTA sample in 81 patients (18.3%), preceding antimicrobial chemotherapy in 95 patients (21.4%) and unknown in 135 patients (30.5%), respectively. The pathogenesis of bronchopulmonary infections is complex and various microorganisms are associated with pathogens of bronchopulmonary infections. Therefore, we should accurately diagnose the pathogens in patients with bronchopulmonary infections. TTA is one of the useful methods that we can accurately detect the respiratory pathogens.

Erythromycin (EM) 長期投与によるStreptococcus pneumoniaeの薬剤感受性および生物学的性状におよぼす影響

From April 1990 to February 1992 two hundred and ten strains of Streptococcus pneumoniae were isolated in the laboratory of Nara Medical University Hospital. Frequency of erythromycin resistant Streptococcus pneumoniae, prescription mode of macrolide antibiotics and biological properties were investigated. 1. Erythromycin resistant Streptococcus pneumoniae was predominantly isolated from the wards of the respiratory unit of Inter- nal Medicine and Pediatrics. 2. Patients with erythromycin resistant Streptococcis pneumoniae were treated with macrolide antibiotics frequently in the respiratory unit of Internal Medicine and Pediatrics. 3. MIC90 of EM, CLDM, MINO and ABPC for Streptococcus pneumoniae was 8.0, 8.0, 8.0 and 1.0 micrograms/ml, respectively, indicating moderate resistance to penicillin derivatives and high resistance to macrolides, particularly EM; some strains showed high levels of MIC over 400 micrograms/ml. 4. Investigations on biological properties using VITEK GPI cards revealed that some erythromycin resistant strains showed less responsiveness to DEX, LAC, PUL and MEL. 5. The survival rate of mice infected with erythromycin resistant strains was longer than that with erythromycin sensitive strains. These findings suggested that the prolonged administration of erythromycin causes a virulence reduction of the organism.