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Biomedical subjects

K Tomono

Publications and source records attributed to K Tomono.

At least 73 records · Page 4Linked to original sources
PubMed1999

[A rare case of lung adenocarcinoma in cavity wall of pulmonary aspergilloma].

A 67-year-old man was admitted with the complaint of hemosputum. Chest X-ray films resulted in a diagnosis of pulmonary aspergilloma, and treatment with intravenous amphotericin B was initiated. However, therapy was discontinued due to renal insufficiency, an adverse effect of amphotericin B. The size of the fungus ball and cavity increased despite treatment with oral itraconazole (200 mg/day). Cavernostomy was performed and the fungus ball was removed from the upper lobe of the left lung. Computed tomographic scans disclosed thickening of the remaining wall of the cavity, with destruction of the ribs. The patient experienced worsening respiratory distress and died. Necropsy revealed adenocarcinoma of the left lung.

Adenocarcinoma↗
PubMed1999

[Factors for the onset of and the exacerbation of tuberculosis. 1. Activities in cytolysis and in apoptotic induction of mycobacteria on human THP-1 derived macrophage].

Cytolysis resulted in cell death was detected with propidium iodide, and apoptosis with Annexin V by using flow cytometry. The more vilurent strain in known murine infections showed the higher cytolytic activity. However in those mycobacterial strains that had the higher cytolytic activity on THP-1 cell, the lower level of apoptosis induction was observed. Addition of IFN-gamma or TNF-alpha to THP-1 derived macrophage did not effect on cytolytic activities nor apoptosis induction. Since mycobacteria with the higher cytolytic activity showed the lower apoptosis induction, it was suggested that apoptosis of human macrophage in mycobacterial infection is a beneficial phenomenon to the host.

Apoptosis↗
PubMed1998

Infections caused by multiple strains of methicillin-resistant Staphylococcus aureus--a pressing epidemiological issue.

The genotype of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from several foci in the same patient was studied to identify the rate of infections caused by multiple MRSA strains during hospitalization. Twenty-one patients with MRSA bacteraemia and other specimens diagnosed between 1990-1994 were studied. Clinical data were retrospectively collected from the medical records. Genotyping of 113 MRSA isolates was performed by pulsed-field gel electrophoresis (PFGE), using the Gene Navigator System. More than one type of MRSA was detected from different foci in eight of 21 (38%) patients, and three types were identified in a single patient. Our results indicate that epidemiological investigations must be conducted carefully, especially in immunocompromised hosts with MRSA bacteraemia, as the probability of infection with multiple strains among these patients is relatively high.

Adult↗
PubMed1998

Escherichia coli O157 interactions with human intestinal Caco-2 cells and the influence of fosfomycin.

It is not clear how Escherichia coli O157 invades human enteric epithelium and causes the haemolytic uraemic syndrome (HUS), and nor has the most appropriate treatment of E. coli O157 infection been established. Verotoxins, leucocytes and proinflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and IL-8, are considered essential for the development of HUS. We used the Caco-2 cell monolayer system, well-known as an in-vitro model of human intestinal infection, to determine how E. coli O157 interacts with intestinal epithelial cells and also studied the influence of fosfomycin on the virulence of the bacteria. Results showed that the E. coli O157 used in this study did not penetrate the Caco-2 cell monolayer system, unlike Salmonella typhimurium SL1344, and verotoxin 1 (VT 1), but not VT 2, translocated across the system. In an in-vitro conventional assay, fosfomycin increased the amount of verotoxins but it did not influence penetration of bacteria and translocation of verotoxins in the Caco-2 cell monolayer system. The production of both IL-8 (a potent neutrophil activator) and TNF-alpha in the human monocytic THP-1 cell line was reduced by fosfomycin-treated basolateral medium in this system. These results indicate that fosfomycin may be a potent drug for preventing HUS caused by E. coli O157 infection.

Anti-Bacterial Agents↗
PubMed1998

Relationship between antimycobacterial activities of rifampicin, rifabutin and KRM-1648 and rpoB mutations of Mycobacterium tuberculosis.

We compared the in-vitro antimycobacterial activities of rifabutin and KRM-1648, two rifamycin derivatives, with that of rifampicin against 163 strains of Mycobacterium tuberculosis. We also evaluated the correlation between the level of resistance to rifampicin, rifabutin and KRM-1648 and genetic alterations in the rpoB gene. All 82 strains susceptible to rifampicin or resistant to rifampicin with MICs < or = 16 mg/L were susceptible to rifabutin and KRM-1648 with MICs < or = 1 mg/L. Seventy-six of 81 strains resistant to rifampicin with MICs > or = 32 mg/L were resistant to both rifabutin and KRM-1648, but with lower MICs than those of rifampicin. KRM-1648 showed more potent antimycobacterial activity than rifabutin against organisms with low MICs (< or = 1 mg/L), while rifabutin was more active than KRM-1648 against organisms with high MICs (> or = 2 mg/L). A total of 96 genetic alterations around the 69 bp core region of the rpoB gene were detected in 92 strains. Alterations at codons 515, 521 and 533 in the rpoB gene did not influence the susceptibility to rifampicin, rifabutin and KRM-1648. Point mutations at codons 516 and 529, deletion at codon 518 and insertion at codon 514 influenced the susceptibility to rifampicin but not that to rifabutin or KRM-1648. With the exception of one strain, all alterations at codon 513 and 531 correlated with resistance to the three test drugs. The resistant phenotype of strains with an alteration at codon 526 depended on the type of amino acid substitution. Our results suggest that analysis of genetic alterations in the rpoB gene might be useful not only for predicting rifampicin susceptibility, but also for deciding when to use rifabutin for treating tuberculosis. Further studies may be required to determine the usefulness of KRM-1648.

Amino Acid Sequence↗
PubMed1998

Analysis of genetic relationships and antimicrobial susceptibility of verotoxin-producing Escherichia coli strains isolated in Nagasaki Prefecture, Japan in 1996.

A total of 19 Escherichia coli O157 isolates were obtained in Nagasaki Prefecture, in the south-western part of Japan, between 1990 and 1996. Pulsed-field gel electrophoresis (PFGE) and computer-assisted analysis were applied to determine genetic relationships among these strains. Fragment patterns of the isolates in Nagasaki, as determined by PFGE, were compared with those of isolates in other areas where large outbreaks and sporadic cases of E. coli O157 infection occurred. Similarity values of all the strains isolated in Nagasaki Prefecture were over 0.65 except for E. coli O26. Some strains were identical to the strains isolated from the areas where large outbreaks occurred. All strains were susceptible to ampicillin, fosfomycin, minocycline, amikacin, ofloxacin and sulfamethoxazole-trimethoprim.

Anti-Bacterial Agents↗
PubMed1998

[Analysis of utility of the phenotyping method on detection of cases infected by multiple strains of methicillin-resistant Staphylococcus aureus (MRSA)].

In this study, we compared the types of methicillin-resistant Staphylococcus aureus (MRSA) isolated from several foci of the same patient to find the incidence of multiple strain infection of MRSA in bacteremia cases. We will also evaluate the utility of the typing methods of phenotyping and genotyping for the above mentioned objective and judge the dissimilarity of clinical characteristics between the single strain infection and multiple strains infection. We studied 21 cases of MRSA bacteremia who were culture-positive both from blood and other foci in the same patient at Nagasaki University Hospital during 1990-1994. Clinical data were retrospectively collected from the patients' records. Phenotyping of all 113 MRSA isolates were done by coagulase typing (I-VIII), production of enterotoxins (SEA-SED) and toxic shock syndrome toxin-1 (TSST-1), hemolysis typing and antibiogram (MIC). In addition, typing of the same isolates were done by Pulsed-Field Gel Electrophoresis (PFGE), using Gene Navigator System as the genotyping. Several types of MRSA were found from different foci in the same patient in 8 of 21 cases (38%) by phenotyping. The same typing results were obtained in 7 of 8 the multiple strains isolated cases by PFGE. Two types were obtained from another case by phenotyping, but by PFGF, 3 types were obtained. We consider that phenotyping method is convenient and reliable for judgment of the difference in types isolated from different foci in the same patient, but PFGE possibly provide us more detailed epidemiological information. The epidemiological investigation must be done very carefully, especially in immunocompromised hosts as MRSA bacteremia cases, because the chance of multiple strains infection is relatively high among these cases.

Bacteremia↗
PubMed1998

[Pulmonary infection in the emphysematous bulla due to Mycobacterium szulgai diagnosed by percutaneus needle aspiration].

A 73-year-old male was admitted to our hospital because of productive cough and infiltrate on the chest roentogenogram. The underlying diseases was found to be multiple myeloma. He received a physical examination in June, 1996. The chest X-ray and CT scan on admission showed an infiltrative shadow with multiple bulla in the left upper lung field. Internal use of antibiotics and drip infusion of IPM/CS were ineffective. The chest X-ray showed air-fluid level in left upper peripheral bullous lesion and a percutaneus needle aspiration of the lung was performed. The specimen was pus with blood and microscopical examination of smears revealed no acid-fast bacilli, but Mycobacterium szulgai was isolated and identified by DNA-DNA hybridization method. The patient was treated with isoniazid and rifampicin, and improved in a few months. There are a few case reports of pulmonary infection due to M. szulgai associated with emphysematous bulla of the lung in Japan. M. szulgai infection of the lung is similar to M. kansasii infection in respect to clinical features (improvement of chest abnormal shadow, efficacy of drug).

Aged↗
PubMed1998

[A study of virulence factors produced by MRSA strains isolated from blood samples].

Toxic shock syndrome toxin-1 (TSST-1) and enterotoxins are important virulence factors produced by Staphylococcus aureus. It is reported that these toxins are associated with septic shock and toxic shock syndrome. We investigated the toxin production and coagulase types of 701 MRSA strains isolated in Sasebo City General Hospital between 1994 and 1996 TSST-1 or/and enterotoxins were detected in 67% of all MRSA strains, and those were detected in 88% of MRSA strains isolated from blood samples. 45% of all MRSA strains produced both TSST-1 and enterotoxin C, and 70% of MRSA strains obtained from blood produced those toxins. Frequency of TSST-1 or/and enterotoxin production by MRSA strains isolated from blood samples was significantly higher than that by MRSA strains isolated from urine and pharynx (p < 0.05), and frequency of both TSST-1 and enterotoxin C production by MRSA isolates from blood was significantly higher than that by MRSA strains isolated from pharyngeal sample (p < 0.05). This study indicated that investigation of virulence factors produced by MRSA might give the useful information on prevention and treatment of MRSA infection.

Bacteremia↗
PubMed1998

Long-circulating immunoliposomal amphotericin B against invasive pulmonary aspergillosis in mice.

We investigated the efficacy of long-circulating immunoliposomal amphotericin B (AmB) against invasive pulmonary aspergillosis in mice using three types of liposomal AmB: conventional liposomal AmB (AmBisome), a long-circulating liposomal AmB and prepared by coating the liposome surface with polyethylene glycol (PEG; PEG-L-AmB), long-circulating immunoliposomal AmB (34A-PEG-L-AmB). The survival rates for mice with invasive pulmonary aspergillosis treated with an intravenous dose of 2 mg of AmBisome, PEG-L-AmB, or 34A-PEG-L-AmB per kg of body weight were 16.7, 83.3, and 100%, respectively. Treatment with 34A-PEG-L-AmB produced a marked reduction in the number of Aspergillus fumigatus organisms in the lungs. Pharmacokinetic studies showed the presence of high AmB concentrations in the plasma of mice treated with PEG-L-AmB (40.8 microg/ml) and in the lungs of mice treated with 34A-PEG-L-AmB (42.3 microg/g). We conclude that 34A-PEG-L-AmB, a long-circulating immunoliposomal AmB, is a promising form of AmB against invasive pulmonary aspergillosis.

Amphotericin B↗
PubMed1998

In vitro activities of quinupristin-dalfopristin and the streptogramin RPR 106972 against Mycoplasma pneumoniae.

The in vitro activities of quinupristin-dalfopristin and streptogramin RPR 106972 were determined with 44 strains of Mycoplasma pneumoniae and compared to those of macrolides, minocycline, and quinolones. All isolates tested were highly susceptible to macrolides and to quinupristin-dalfopristin (MIC at which 90% of the isolates are inhibited [MIC90], 0.0625 microg/ml), followed by RPR 106972 (MIC90, 0.5 microg/ml), quinolones, and minocycline.

Anti-Bacterial Agents↗
PubMed1998

Efficacy of NS-718, a novel lipid nanosphere-encapsulated amphotericin B, against Cryptococcus neoformans.

In vitro and in vivo efficacies of NS-718, a lipid nanosphere-encapsulated amphotericin B (AMPH-B), have been studied. Of the tested AMPH-B formulations, NS-718 had the lowest MIC for Cryptococcus neoformans. In a murine model, low-dose therapy (0.8 mg/kg of body weight) with NS-718 showed higher efficacy than that with AmBisome. High-dose therapy (2.0 mg/kg) with NS-718 was much more effective than those with Fungizone and AmBisome. In mice treated with a high dose of NS-718, only a few yeast cells had grown in lung by 7 days after inoculation. A pharmacokinetic study showed higher concentrations of AMPH-B in lung following administration of NS-718 than after administration of AmBisome. Our results indicated that NS-718, a new AMPH-B formulation, is a promising antifungal agent for treatment of pulmonary cryptococcosis and could be the most effective antifungal agent against C. neoformans infections.

Amphotericin B↗
PubMed1998

Rapid detection and evaluation of clinical characteristics of emerging multiple-drug-resistant gram-negative rods carrying the metallo-beta-lactamase gene blaIMP.

Gram-negative rods (GNR) carrying the transferable carbapenem resistance gene blaIMP, including Pseudomonas aeruginosa and Serratia marcescens, have been isolated from more than 20 hospitals in Japan. Although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution of blaIMP-positive GNR in hospitals and the clinical characteristics of infected patients is available. To address this, a system for the rapid detection of the blaIMP gene with a simple DNA preparation and by enzymatic detection of PCR products was developed. A total of 933 ceftazidime-resistant strains of GNR isolated between 1991 and 1996 at Nagasaki University Hospital, Nagasaki, Japan, were screened for the blaIMP gene; 80 isolates were positive, including 53 P. aeruginosa isolates, 13 other glucose-nonfermenting bacteria, 13 S. marcescens isolates, and 1 Citrobacter freundii isolate. Most of the patients from whom blaIMP-positive organisms were isolated had malignant diseases (53. 8%). The organisms caused urinary tract infections, pneumonia, or other infections in 46.3% of the patients, while they were just colonizing the other patients evaluated. It was possible that blaIMP-positive P. aeruginosa strains contributed to the death of four patients, while the other infections caused by GNR carrying blaIMP were not lethal. DNA fingerprinting analysis by pulsed-field gel electrophoresis suggested the cross transmission of strains within the hospital. The isolates were ceftazidime resistant and were frequently resistant to other antibiotics. Although no particular means of pathogenesis of blaIMP-positive GNR is evident at present, the rapid detection of such strains is necessary to help with infection control practices for the prevention of their dissemination and the transmission of the resistance gene to other pathogenic bacteria.

DNA Fingerprinting↗
PubMed1998

Adherence to and penetration of human intestinal Caco-2 epithelial cell monolayers by Pseudomonas aeruginosa.

Clinical isolates of Pseudomonas aeruginosa from blood adhered to and penetrated intestinal Caco-2 cell monolayers to a greater degree than did isolates from sputum, with a concomitant drastic decrease in transepithelial electrical resistance. PAO-PR1, an avirulent exotoxin A mutant of PAO1, did not cause a decrease in the resistance. The Caco-2 monolayer system may be useful for the evaluation of certain P. aeruginosa virulence factor activities.

Bacterial Adhesion↗
PubMed1998

Genetic relationship between blood and nonblood isolates from bacteremic patients determined by pulsed-field gel electrophoresis.

A total of 148 isolates from 55 bacteremic patients were examined by pulsed-field gel electrophoresis. Genetically different nonblood strains were isolated from 13.9% of patients with bacteremia caused by gram-positive cocci and 42.1% with Pseudomonas aeruginosa bacteremia, indicating that antibiograms of a single nonblood P. aeruginosa isolate are not always informative for treatment of bacteremia.

Bacteremia↗
PubMed1998

Antimicrobial susceptibility testing of Bilophila wadsworthia isolates submitted for routine laboratory examination.

MICs of antibiotics against Bilophila wadsworthia isolates were measured by agar and broth microdilution with pyruvic acid and by Etest. The inoculum size influenced greatly agar dilution. Despite discrepancies in MICs depending on the measurement method used, clindamycin consistently showed potent activity. Broth microdilution and Etest appear to be candidates for laboratory susceptibility testing.

Aged↗
PubMed1998

Detection of Mycobacterium tuberculosis in preserved tuberculous lymph nodes by polymerase chain reaction.

We evaluated the usefulness of three types of polymerase chain reaction (PCR) targeting 16S rRNA, protein antigen b and IS6110 in detecting Mycobacterium tuberculosis in preserved tuberculous lymph nodes. The detection limit of all PCR methods was 100 colony forming unit (CFU) of M. tuberculosis in tissue. The test samples included eight paraffin-embedded tuberculous lymph nodes containing microscopical epithelioid cell granuloma with caseous necrosis and Langhans giant cells. Although acid-fast stained organisms in lymph node tissue were not detected in any sample, all three types of PCR tests were positive in four of eight lymph nodes. Our results suggest that PCR is not only a rapid and sensitive diagnostic method for tuberculous lymphadenitis, but also clinically significant in retrospective study for detecting M. tuberculosis even in some preserved lymph node tissues without evidence of acid-fast stained organisms.

Antigens, Bacterial↗