227 DIFFERENTIATION OF HEPATOCYTE-LIKE CELLS FROM MOUSE EMBRYONIC STEM CELLS IN A MONOLAYER CULTURE SYSTEM

Embryonic stem (ES) cells can be differentiated in vitro into a variety of cell lineages. In vitro differentiation of ES cells, therefore, provides a model system for organogenesis as well as an innovative approach for regenerative medicine. However, current in vitro hepatic differentiation systems from ES cells require embryoid body formation, and such systems achieve quite low differentiation efficacy. In this study, in order to examine a system for preparation of significant numbers of hepatocytes from ES cells, mouse ES cells were directly differentiated into hepatocyte-like cells using monolayer culture conditions, and their hepatic characteristics were examined. ES cells were cultured on gelatin-coated plates for 3 days in ES cell medium containing leukemia inhibitory factor (100 units mL-1) and retinoic acid (10-8 M). After 3 days, the cells were harvested by trypsinization and cultured on gelatin-coated plates for 5 days in ES cell medium containing acidic fibroblast growth factor (aFGF; 100 ng mL-1), FGF4 (20 ng mL-1), and human growth factor (50 ng mL-1). After 5 days, the cells were passaged on type I collagen-coated plates for 2 days in ES cell medium containing Oncostatin M (10 ng mL-1), followed by additional culture in modified William's E medium containing 5% FBS and dexamethasone (10-7 M) for 7 days. For characterizing the differentiated ES cells, the cells were examined for albumin production by immunocytochemistry, and the expression profiles of hepatic genes by RT-PCR. For analyzing their hepatic function, the cells were examined for glycogen production by PAS staining, and their metabolic activities of ammonia elimination and urea synthesis were measured. After 10 days of culture, almost all cells showed albumin production by immunofluoresence. RT-PCR analysis showed expression of various genes specific for hepatocytes, such as ALB, AFP, TTR, and HNF3�, but not HNF4α, and genes specific for matured hepatocytes, such as PEPCK, TAT, G6P, and Cyp7a1. After 11 days of culture, glycogen production was partially detected in the hepatocyte-like cells by PAS staining. Although ammonia elimination activity of hepatocyte-like cells was shown to be significantly lower than that of the primary culture of fetal hepatocytes after 24 and 48 h of treatment (P < 0.05), its metabolic activity was acquired at the level of about 40% of that of fetal hepatocytes. Hepatocyte-like cells also showed lower activity of urea synthesis than fetal hepatocytes at 6, 12, and 24 h of treatment (P < 0.05), but this activity increased thereafter and reached about 70% of that of fetal hepatocytes after 48 h of treatment. These results demonstrated that monolayer culture conditions for ES cell differentiation could provide an in vitro system to produce significant numbers of hepatocytes. This work was supported by a Grant-in-Aid for the 21st Century Center of Excellence Program of the MEXT, Japan, and by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science.

[Pathogenetic study on bronchopulmonary infections in 1,416 patients by transtracheal aspiration method]

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.

[Acute exacerbations due to Streptococcus pneumoniae in chronic lower respiratory tract infections during long-term macrolide therapy]

In Japan, long-term 14-membered macrolide administration is chosen as a first line therapy against chronic lower respiratory tract infections (CLRTIs) such as diffuse panbronchiolitis, bronchiectasis and chronic bronchitis. However, sometimes acute exacerbations occur in these cases, even if therapy is effective. We investigated 18 episodes of CLRTIs exacerbations that were caused by Streptococcus pneumoniae during long-term macrolides therapy from 1991 to 1999 to clarify the clinical features and prevalence of antimicrobial resistance in S. pneumoniae. Exacerbations did not occur only in winter season, but also in other seasons. Among 18 episodes of exacerbation, only 7 episodes (39%) revealed infiltration in chest roentogenogram and few episodes revealed marked elevations of inflammation markers in laboratory data. Intermediate resistance or resistance rates of S. pneumoniae isolated from sputum or transtracheal aspiration were 100% to erythromycin, 67% to clindamycin or minocycline, 11% to ampicillin, and 0% to cephazoline or imipenem. Coresistance to erythromycin, clindamycin and minocycline was seen in a half of the episodes. Resistance was not correlated with the duration of macrolides administration. All episodes were mainly treated with beta-lactam agents or fluoroquinolones and cured successfully. These findings suggest that acute exacerbations in CLRTIs caused by S. pneumoniae during long-term macrolides therapy do not reveal severe clinical aspects and can be treated successfully at present, but attention should be paid to the trend of antibiotic susceptibility in S. pneumoniae.

A novel missense mutation in human lactate dehydrogenase B-subunit gene

Reduced activity of serum lactate dehydrogenase (LDH; EC 1.1.1.27) was found in a male medical student during practical examinations of his own blood. Serum LDH isoenzyme pattern showed reductions in activities of the isoenzymes with lower subunit A/B ratios such as LDH1 and LDH2. These findings were indicative of a partial LDH-B subunit deficiency, which was confirmed in erythrocyte hemolysates by Western blotting. Polymerase chain reaction (PCR)-based DNA sequence analysis of the LDH-B subunit gene revealed a heterozygous nucleotide change: a guanine to adenine substitution in codon 69 (GGG --> GAG) at the third exon of the LDH-B subunit gene that resulted in a glycine to glutamic acid substitution (G69E). The mutation was confirmed by PCR-restriction fragment length polymorphism (RFLP) analysis using a mismatched primer to introduce a new NcoI restriction site. The same heterozygous mutation was found in his mother but not in other family members. This mutation involves a residue belonging to alphaC helix in LDH-B subunit protein molecule that functions as an interface for other subunits.

[Enterococcus gallinarum septicemia in a patient with acute myeloid leukemia]

A 62-year-old male was admitted with complaints of fever and body weight loss. The patient was diagnosed as acute myeloid leukemia (M1) and chemotherapy was started. About 80 days after admission, the patient developed diarrhea with high fever. And E. gallinarum was isolated from the blood culture. We carried out PCR using primers for vanA, vanB and vanC in our E. gallinarum, and showed the existence of the vanC1. This organism should be considered as one of the possible pathogenes in the infectious complications of the immuno-compromized patient.

[Clinical evaluation of anaerobic infections in patients with bronchopulmonary infections diagnosed by transtracheal aspiration]

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.

[Bacillus cereus septicemia in a patient with severe aplastic anemia]

A 78-year-old female was admitted with complaints of malaise and fatigue in the legs. The patient was diagnosed as severe aplastic anemia and treatment was started with metenolone and steroid pulse therapy. Administration of antibiotics and granulocyte-colony stimulating factor which led to a resolution of the high fever. About four months after admission, the patient developed vomiting and abdominal pain with a spiking fever. The next day after suddenly losing consciousness, she died. B. cereus was isolated from blood cultures. Autopsy specimens of the liver, cardiac muscle and lung showed changes due to B. cereus. This pathogen is widely distributed in nature. We should not overlook B. cereus as a contamination, but rather should consider it a potential pathogen in immunocompromised hosts, when it is isolated from blood cultures.

[Clinical evaluation of lung abscess diagnosed by transtracheal aspiration]

We have diagnosed lung abscess according to findings of infiltration with cavity formation on chest X-ray and/or CT-scan and pathogens isolated from transtracheal aspirates. We evaluated the clinical features of 20 patients with lung abscess (18 males and 2 females, mean age; 54.3 years). Diabetus mellitus and periodontal diseases were prominent underlying diseases in patients with lung abscess. Cough was complained in 13 patients, chest or back pain in 9, purulent sputum in 8 and hemosputum in 5 when the patients admitted to our hospital. A temperature higher than 38 degrees C was present in 12 patients but temperature les than 37 degrees C in 2. Multiple microorganisms were cultured from TTA in 15 patients. A mean of 2.7 bacterial species per patient was isolated, aerobes alone being isolated in 2 patients, anaerobes alone in 3, and mixed aerobic and anaerobic isolates in 10. Seventeen strains of aerobes and 35 of anaerobes were isolated. Major pathogens were Streptococcus pneumoniae, Streptococcus intermedius and other in aerobes, and Peptostreptococcus micros, Fusobacterium necrophorum, Prevotella melaninogenica and others in anaerobes. Abnormality of chest X-ray was located on the right upper lobe in 6 patients, the right lower lobe in 6, the left upper lobe in 6, the left lower lobe in 4 and the right middle lobe in 1. All patients were cured only by treatment of antimicrobial agents, but cavity formation on chest X-ray remained in 4 patients after the treatment.

[A clinical study of respiratory infection isolating non-pathogenic Neisseria by transtracheal aspiration]

Neisseria species other than N. meningitidis and N. gonorrhoeae are generally regarded as commensal bacterial flora of the oropharynx, and little is known regarding cases of these non-pathogenic Neisseria species in the lower respiratory tract. We clinically examined respiratory tract infections from which non-pathogenic Neisseria species were isolated by transtracheal aspiration (TTA). The incidence of non-pathogenic Neisseria isolated was 54 (15.7%) out of 344 episodes of respiratory tract infections with isolated microorganisms from TTA, and was 17.6%, 15.8%, 14.3% for pneumonia, acute bronchitis, and chronic lower respiratory tract infection, respectively. All 54 episodes were isolated with other microorganisms such as alpha-Streptococcus spp. (75.9%), Haemophilus influenzae (25.9%) and anaerobics (22.2%). The isolation ratio according to the age group increased at 45 years of age or more, but did not increase with the advance of age. Predisposing factors were identified such as overt aspiration, iatrogenic procedure and heavy smoking. Cases without overt aspiration that had fevers of 38 degrees C or more or hypoxemia of less than PaO2 70 torr when detecting non-pathogenic Neisseria were observed more frequently in the aged than the non-aged. The findings suggest the detection of non-pathogenic Neisseria by TTA is influenced by the host state that the fall of microorganisms from the upper to lower respiratory tract cannot be defended or excluded by mucociliary transportation disorder due to underlying disease and smoking, or deterioration of physical status other than overt or silent aspiration.

[Two cases of Achromobacter xylosoxidans sepsis]

Achromobacter xylosoxidans is a gram-negative bacterium whose natural habitat has not been clearly defined. It has been isolated from ear discharge and the large intestine of humans and from various hospital or environmental water sources. Infection with A. xylosoxidans in humans has been documented, and resulting illnesses include meningitis, pneumonia, cholecystitis, peritonitis and urinary tract infection. Bacteremia due to A. xylosoxidans is rare, and little information on treatment is available. Two cases of bacteremia due to A. xylosoxidans in patients with hemapoietic malignancies are reported herein. Case 1 involved a 70-yr. male whose clinical diagnosis was IgA lambda-type plasmacytoma. Case 2 involved 72-yr. male whose clinical diagnosis was acute lymphatic leukemia (L2). Both patients had been catheterized. Neutropenia was noted and the white blood cell counts were 20/microliter in case 1 and 35/microliter in case 2 when A. xylosoxidans was isolated from the blood culture. We suggest that bacteremia due to A. xylosoxidans may have been related to the presence of the catheter and neutropenia.

[An epidemiological investigation for MRSA and PRSP in Kinki area. Kinki Infection Working Group]

Recent trends in the development of resistance of the Staphylococcus aureus and Streptococcus pneumoniae to antibiotics were investigated, using a questionnaire delivered to participants at a meeting of the Kinki District Society of Infections. Methicillin-resistant Staphylococcus aureus (MRSA) accounted for 55.4% of all isolated S. aureus, and more than 80% of MRSA was detected within hospitals. In outpatients, MRSA was often detected in pus, while in hospitalized patients, MRSA was often detected in sputum. Further, MRSA was accompanied by some other organisms (most frequently Pseudomonas aeruginosa) in 64.7% of MRSA positive patients. The sensitivity of MRSA to vancomycin (VCM) was 100%, to sulfamethoxazole-trimethoprim (ST) 99.2%, and to arbekacin, 98.6%. In contrast, Penicillin-resistant Streptococcus pneumoniae (PRSP) accounted for 42.4% of all isolates of Streptococcus pneumoniae. About 50% of PRSP was detected in out-patients. For both hospitalized patients and outpatients, PRSP was most frequently detected in sputum. PRSP was accompanied by some other organisms (most frequently Haemophilus influenzae) in 49.3% of PRSP positive patients, PRSP had high sensitivity to cephems, carbapenems and VCM.

[Clinical analysis of patients with sepsis--comparison between underlying diseases]

We evaluated the clinical data in 83 patients with sepsis, which was diagnosed by both Bone's definition of sepsis and positive isolates from blood culture, according to their underlying diseases. This study enrolled a total of 117 septic episodes in 83 patients (57 males and 26 females, mean age: 52.0 years). We classified 3 groups, including hematological malignancies (46 patients, 72 episodes), solid malignant tumors (23 patients, 25 episodes) and non-malignancies (14 patients, 20 episodes), by the underlying diseases. Of the total number of isolates from blood culture, 53.0% were single gram-positive bacteria, 33.3% were single gram-negative bacteria, 7.7% were single fungus and 6.0% were polymicrobial organisms. In addition, coagulase negative staphylococci was isolated most often in patients with hematological malignancies. Sepsis was often caused by infectious focuses of hemorrhoid, stomatitis or intravenous catheter in patients with hematological malignancies, by pneumonia in patients with solid malignant tumors and by urinary tract infection in patients with non-malignancies. Mortality of sepsis in patients with solid malignant tumors (48%) was highest in 3 groups. Septic patients, who were complicated with shock and/or DIC, has poor prognosis in all groups. Serum albumin level was significantly lower in dead patients than patients who survived. These results suggest that clinical features may be different according to the underlying diseases of patients with sepsis.

[Campylobacter jejuni enteritis in three patients with HIV infection]

Gatrointestinal symptoms, which include diarrhea, are as common as respiratory symptoms in patients with HIV infection. Gastrointestinal symptoms may result from infections, neoplasma, HIV enteropathy or drug toxicity. Three HIV-infected patients admitted to our hospital complaining of diarrhea and fever. We confirmed their diagnosis as Campylobacter jejuni enteritis by bacteriological examination of their feces. All of them had eaten inadequately cooked meat in restaurants before the onset of their enteritis. Their symptoms immediately improved after the administration of antimicrobial agents. One strain of C. jejuni isolated in our cases, however, was resistant to ofloxacin. This case report suggests that we must counsel HIV-infected patients to avoid inadequately cooked food and observe resistant patterns of C. jejuni to antimicrobial agents in Japan in the future.

[A case of multiple muscular abscesses of the lower limbs by Staphylococcus aureus after chemotherapy for lung cancer]

A 67-year-old male was admitted to our hospital because of lung cancer and interstitial pneumonia. Cisplatin, vindesie and mitomycin C were administered for treatment of lung cancer. The leucocyte-counts declined to 1700/microliter on the eighth day after the chemotherapy. Though granulocyte colony-stimulating factor was administered, pain in the right thigh and high grade fever developed. Because Staphylococcus aureus was isolated from the blood specimen, piperacillin was administered. But the high grade fever continued and the pain was expanded to the right hip, left hip, thigh and leg. Because a computed tomograph of the lower limbs showed low density areas in bilateral gluteus maximus muscle right adductor magnus muscle, left biceps femoris muscle and left soleus muscle and the culture of an aspirate from abscess of right leg detected S. aureus, multiple muscular abscesses of the lower limbs was confirmed. We changed the antibiotics from PIPC to imipenem/cilastatin and minocycline on nineteenth day after the chemotherapy. His symptoms improved after the change of antibacterial agents. But he died of acute exacerbation of interstitial pneumonia, after about two months of the chemotherapy. Muscular abscesses of the limbs are very rare in Japan. Only four cases with muscular abscess of the limbs were reported in Japan, since 1988. This case suggests that a muscular abscess must be considered in the differential diagnosis of fever in patients with neutropenia.

[Prognostic analysis of sepsis in patients with lung cancer]

Sepsis is one of the most serious infections occurring in patients with lung cancer. Thus, we determined what is most predisposing factor in prognosis of sepsis in lung cancer patients; the type of causative bacteria, neutropenia or host nutritional status. A total of 27 lung cancer patients with sepsis, which consisted of 23 males and 4 females (mean age 70.7 +/- 6.6), were included in this study. The study was conducted from 1991 to 1995. All subjects were classified into the survival group and the dead group. Staphylococcus aureus or Esherichia coli most frequently isolated from the blood of the patients in the survival group, while either E. coli alone or multiple organisms were predominant in the dead group. Neutropenia did not affect the outcome of sepsis in lung cancer patients. In contrast nutritional status, as determined by serum albumin levels, was closely related to the mortality in septic lung cancer patients. These results predict that the prognosis of sepsis is dependent on nutritional status of lung cancer patients.

[Analysis of prognosis of bronchopulmonary infectious disease with lung cancer]

Bronchopulmonary infection affects the prognosis of lung cancer patients. Thus, we investigated the relationship between the prognosis of bronchopulmonary infectious diseases and their causative bacteria isolated by transtracheal aspiration (TTA) in lung cancer patients. In the present study, we determined which factor is more predisposing for the outcome of bronchopulmonary infections, the type of causative bacteria or the host nutritional status. A total of 107 lung cancer patients, which consisted of 105 males and 5 females (mean age 67.3 +/- 8.0), were included in this study. The study was conducted from 1981 to 1994. They were classified into the survival group and the deceased group. Causative agents of infection were compared between these 2 groups. S. pneumoniae, alpha-Streptococcus sp., M. catarrhalis, and Neisseria sp. were predominant in organisms isolated from TTA-specimens of lung cancer patients with bronchopulmonary infections, regardless of prognosis. Nutritional status, as determined by serum levels of cholinesterase, albumin, and cholesterol, was poor in the deceased group than in the survival group. These results indicate that the outcome of bronchopulmonary infections in lung cancer patients are affected mainly by the nutritional status of the host.

[A clinical features of acute respiratory infection with Haemophilus influenzae by transtracheal aspiration]

We performed a clinical study of 26 cases (27 episodes) of acute respiratory infection with H. influenzae by trans tracheal aspiration (TTA) from May 1987 to April 1995. 15 episodes (14 cases) were bronchitis and 12 episodes (12 cases) were pneumonia. 8 episodes were monomicrobial infection and 19 episodes were polymicrobial infection. Compared to the group of patients of monomicrobial infection, the number of elderly patients and the levels of WBC and CRP were higher in the group of patients of monomicroibal infection. In bronchitis cases, monomicrobial infections of H. influenzae were 7 episodes and polymicrobial infection containing H. influenzae were 8 episodes. In the latter group, PaO2 level was lower and CRP was higher on average. All patients recovered, but the period for treatment was longer in the latter group. In the pneumonia group, only one episode was monomicrobal infection and 11 episodes were polymicrobial infection. Inspite of treatment, one patient died. It was considered that polymicrobial infection was an important factor of acute respiratory infection with H. influenzae.

[A case of AIDS with intractable cryptococcal meningitis]

A 38-year-old hemophiliac, who had been infected with HIV by the administration of blood products and had been diagnosed as AIDS by the onset of Pneumocystis carinii pneumonia, was admitted to our hospital with the complaints of headache and vomiting. After he was diagnosed as cryptococcal meningitis using the microscopy, cryptococcal antigen detection and culture of cerebrospinal fluid, treatment with amphotericin-B and fluconazole was started. As there was no clinical improvement, spinal drainage was performed and acetazolamide administered in order to reduce the intracranial pressure. Treatment was changed from AMPH-B and FLCZ to a combined therapy of AMPH-B and itraconazole. As his clinical features showed improvement, he was discharged home on a maintenance dose of ITCZ and acetazolamide after having been hospitalized for three months. This case-report may be of use in the management of cryptococcal meningitis in patients with AIDS.

[Effect of prolonged administration of erythromycin on the drug sensitivity and the biological properties of Streptococcus pneumoniae]

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.

[A case of sepsis due to Escherichia coli isolated from blood, transtracheal aspiration and urine]

We reported a 53-year-old female who was admitted due to partial loss of consciousness. She had been diagnosed as old pulmonary tuberculosis and diabetes mellitus. She was diagnosed as diabetic keto-acidosis on admission. We isolated Escherichia coli in the blood, transtracheal aspiration (TTA) and from the urine. We have experienced 6 cases where the same bacteria was isolated from the blood and TTA at the same time. In all 6 cases, we have found single bacteria in the blood and a few other bacteria in TTA. Blood culture is the most certain method to detect the origin of infectious diseases. But the compromised host, as in this case, has multifocal infections in many cases. In order to understand the pathological aspects of the infection, we must obtain many kinds of samples and as many as possible.

[Clinical study of anaerobic respiratory infection]

This clinical study involved 35 cases, anaerobic bacteria were detected by TTA (transtracheal aspiration) or percutaneous lung aspiration, or pleural puncture. These cases were treated over the last 8 years in our department. There were 9 empyema, 9 pneumonitis, 5 lung abscess, 1 necrotizing pneumonia and 11 chronic lower airway infection. In 13 cases (37%), anaerobic bacteria alone were detected, whereas both anaerobic and aerobic bacteria were observed in the other 22 cases (63%). Of all bacteria detected. Bacteroids and Peptostreptococcus were the most common. With respect to host factors involved in the pathogenesis of pleural and parenchymal infection, aspiration was though to be a major trigger in only 11 out of the 24 cases (46%). The other 13 cases (54%) showed no evidence of aspiration, indicating that some other triggers was responsible. In further study, these 13 cases were found either to be heavy smokers with Brinkman index of more than 600, or to show sign of chronic lower airway infection. Both conditions were characterized by an inhibition of the mucociliary transport in the lower airway. Therefore, this study suggested that in the case without apparent aspiration the failure of local defense mechanisms in the airway, as a result of heavy smoking and/or chronic lower airway infection are involved in the pathogenesis of anaerobic respiratory infection.

[Long-term chemotherapy using erythromycin (EM) for chronic lower airway infection: effectiveness of clarithromycin in EM ineffective cases--the fourth report]

The effectiveness of long-term chemotherapy using Erythromycin (EM) for chronic lower airway infection has been practically proved. However, there still exist some ineffective cases, or cases in which the clinical effect was scarcely seen. In the present study was administered Clarithromycin (CAM) to such cases and found that CAM was effective in alleviating symptoms in some of them. The results were presented along with clinical findings and other basic studies. The subjects were 4 cases in which EM was either ineffective or low in its clinical effect. The subjects consisted of 1 case of DPB and 3 cases of bronchiectasis. EM was clinically ineffective in 2 cases and slightly effective in the two others. The pathogen was Pseudomonas aeruginosa in all cases. The dosage of EM was 200-1200 mg/day. The period of administration ranged from 2 years to 6 years 9 months. CAM was given orally after meals at a dose of either 200 or 400 mg/day. Chemotherapy had continued for 3-8 months at the time of final observation (Feb. 1992). Clinical effectiveness was evaluated on the basis of sputum volume and PaO2 examination, as well as evaluation by the patients themselves. As a result, in all 4 cases, reduction in sputum volume and improvement of PaO2 were observed. All subjects evaluated CAM therapy as being more effective than EM therapy. Moreover, it was found that CAM inhibited both the elastase and leucocidin produced in one of the ineffective cases by P. aeruginosa, whereas EM didnt.(ABSTRACT TRUNCATED AT 250 WORDS)

[The long-term chemotherapy with erythromycin (EM) in chronic lower respiratory tract infections--third report: clinical study of cases administered EM over 3 years]

An investigation was made of the use of EM therapy which began in 1986 or earlier in 31 cases with chronic lower respiratory tract infections. 1) Of the 20 cases in which EM (Erythromycin stearate) administration (600-1200 mg/day) was continued for 3 years or more and its usefulness could be evaluated, treatment with this agent was judged markedly effective in three, effective in 14, somewhat effective in two, and ineffective in one. This amounted to an effectiveness rate (effective or better) of 85%. 2) Improved QOL was observed in 15 of the 20 cases. 3) In the Pseudomonas infected cases, a discrepancy was seen between the effectiveness rate of 87.5% and the disappearance rate of the organism (12.5%), while in the Haemophilus cases no such discrepancy was found (75%). 4) EM administration was stopped in 11 cases because of side effects in two (stomatitis, gastrointestinal disorder) death in five, desire of the patient in three, and transfer to another hospital in one. The cause of death cases had no connection with administration of EM. 5) In the three patients who stopped EM on their own, the agent was again administered because of exacerbation of symptoms, although this readministration proved ineffective in two of the cases. The above results suggest that long term EM therapy is useful and that its continued administration is important.

[A clinical study of respiratory tract infection due to Staphylococcus aureus detected by transtracheal aspiration]

A clinical study of 24 patients with respiratory tract infection due to S. aureus detected by transtracheal aspiration (TTA) was conducted, and the following results were obtained. 1) The detection frequency of S. aureus was relatively low (4.6%). 2) Pneumonia was the principal clinical manifestation. 3) Approximately one half of the patients had previously received antimicrobials. 4) Multiple organisms were frequently detected, particularly in cases of hospital-acquired infection. H. influenzae was the most frequently simultaneously detected organism. 5) On sputum examination, approximately 20 ml of purulent sputum was found in most cases, and S. aureus was detected in sputum specimens from 20 of the patients. 6) The largest number of cases was found in 1987. Onset was most common from autumn to spring. 7) Undernutrition was the most frequently associated host factor. As indicated by the above findings, the clinical expression of S. aureus infection is variable, and it is important that it be diagnosed accurately.

[A clinical study on five cases of respiratory infections caused by Neisseria meningitidis]

Five cases of the respiratory infections, in which Neisseria meningitidis was isolated upon the examination of the transtracheal aspiration (TTA), were reported. Patients studied were four males at the ages of 18, 56, 66 and 78 years, and a 18-year old female. Five cases were bronchopneumonia (two cases), acute bronchitis (two cases) and diffuse panbronchiolitis (DPB) (one case). Underlying diseases were as follows: lung cancer or acute myocardial infarction in cases of bronchopneumonia, and interstitial pneumonia or pulmonary tuberculosis in cases of acute bronchitis. There was a case in which only N. meningitidis was cultured from specimens obtained by TTA, although another different organism, in addition to N. meningitidis, was recovered from the patient of other cases. Other organisms found together with N. miningitidis were H. influenzae (2 cases), S. dysgalactiae (1 case) and M. tuberculosis (1 case). Predisposing factors were common cold in the female patient and bronchoscopic examination in the cases of lung cancer and of interstitial pneumonia. Two of the five cases occurred consecutively in the same room and so they were considered as nosocomial infections. With these findings, it can be posturated that N. meningitidis might be one of the etiological agents of the respiratory infections.

Grayanotoxin opens Na channels from inside the squid axonal membrane

External application of alpha-dihydro-grayanotoxin II (alpha-H2-GTX II) to squid giant axon under nonperfused condition caused substantial membrane depolarization. Intracellular perfusion of the fibers retarded this depolarization appreciably. Tritium-labeled alpha-dihydro-grayanotoxin II ([3H]alpha-H2-GTX II) in the external medium can permeate through the cell membrane, but permeation of alpha-H2-GTX II does not occur either with the carrier-mediated system or through the pores of the Na channel. The finding that the most hydrophilic grayanotoxin analogue, desacyl asebotoxin VII, is effective only when applied internally, strongly suggests that the receptor for grayanotoxin does not exist on the external surface of the membrane. The linear relationship between the concentration of [3H]alpha-H2-GTX II in the external medium and the count in the effluent from the perfused axon indicates that GTX II diffuses through the cell membrane's lipid phase and reaches the site of action only approached from the internal medium.

[The antibacterial activity of new cephem antibiotics against clinical isolates. A comparison of the antibacterial activity of cefotaxime with 6 other antibiotics]

During the period from May through July 1981, a comparative study was carried out on the antibacterial activities of cefotaxime (CTX) and ceftizoxime (CZX), cefoperazone (CPZ), latamoxef (LMOX), cefotiam (CTM), cefmetazole (CMZ) and cefazolin (CEZ). CTX and these other cephem antibiotics were tested against fresh clinical isolates which had been obtained from clinical materials by the laboratories of 14 participating medical institutions. 1. The clinical isolates were obtained from various clinical materials in the following decreasing order: urine, sputum and pus/discharge; 85.7% of the isolates came from these materials. 2. Concerning the sources of each species of clinical isolates, it was found that P. aeruginosa was isolated from the greatest number -9- of different clinical materials. This was followed by E. coli and E. cloacae, each isolated from 8 different clinical materials, and C. freundii and E. aerogenes, each found in 7 different clinical materials. 3. In relation to S. pyogenes, S. agalactiae and S. pneumoniae, CTX showed the best antibacterial activity; the second most potent antibiotic was CZX. CMZ and LMOX were found to show relatively high MIC values for those species. Against S. aureus, CEZ showed the best antibacterial activity, but 3 resistant strains had MICs of greater than 100 micrograms/ml. 4. With regard to Gram-negative bacteria, CTX and CZX showed the best antibacterial activities for all of the species, except for P. aeruginosa. These were followed, in order, by LMOX and CPZ. Compared with these 4 antibiotics, CTM, CMZ and CEZ were found to have inferior antibacterial activities against these bacteria. In relation to P. aeruginosa, the peak of the MIC distribution for CPZ was 6.25 micrograms/ml, and this was the best antibacterial activity detected with the various antibiotics tested. This was followed by CTX (25 micrograms/ml) LMOX (25 micrograms/ml) and CZX (50 micrograms/ml). CTM had an MIC of 100 micrograms/ml for 1 strain, and MICs of greater than 100 micrograms/ml for all of the other strains of P. aeruginosa, indicating them to be resistant to this antibiotic. All of the strains were resistant to CMZ and CEZ, showing MICs of greater than 100 micrograms/ml. 5. For each of the tested antibiotics, no correlation was found between the MIC and the serogroup for either P. aeruginosa or S. marcescens.

Structure-activity relationship for grayanotoxin derivatives in frog skeletal muscle

In the presence of biologically active grayanotoxins, the frog skeletal muscle fiber generated a spontaneous action potential which was followed by a sustained depolarization. This depolarization was due to the specific increase in the membrane permeability to sodium, as it was abolished by withdrawal of sodium from the external medium or application of 1 x 10(-6) M tetrodotoxin. Potencies of biological activity of 34 grayanotoxin analogs were estimated from the measurement of critical concentrations for spontaneous generation of a prolonged action potential. It was found that the biological activity of grayanotoxins was largely dependent on both stereospecificity and hydrophobicity of the molecules. The essential groups in the grayanotoxin molecules for the biological activity were determined to be 3 beta-OH or 2 beta, 3 beta-epoxy group, 5 beta-OH, 6 beta-OH and 10 beta-methyl groups. There was an optimal hydrophobicity of the molecule for the maximal biological activity. Either increase or decrease in the number of OH groups from the optimal number of five reduced the biological activity. Four essential groups corresponding to those in the grayanotoxin molecules are also present in the molecules of veratridine, batrachotoxin and aconitine, all of which are known to keep the sodium channel open.