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Biomedical subjects

K Yanagihara

Publications and source records attributed to K Yanagihara.

At least 91 records · Page 5Linked to original sources
PubMed1997

"Reversed" latissimus dorsi musculocutaneous flap for closure of large bronchopleural fistula.

The patient was a 54-year-old male with diabetes mellitus and liver abscess perforating into the right lung through the diaphragm. After right lower lobectomy of the lung, S3-segmentectomy of the liver, and debridement of the subdiaphragmatic abscess a bronchopleural fistula appeared. After open-drainage thoractomy, secondary operation for closure of a large bronchopleural fistula and obliteration of the empyema cavities was performed with a "reversed" latissimus dorsi musculocutaneous flap.

Bronchial Fistula↗
PubMed1997

[Genetic evaluation for rifampicin-susceptibility of Mycobacterium tuberculosis].

We evaluated the relationship between rifampicin (RFP)-susceptibility and genetic alterations in rpoB gene of clinically isolated Mycobacterium tuberculosis strains, collected from different geographic locations within Japan. Alterations in rpoB gene were detected by PCR-direct sequencing analysis, and the minimum inhibitory concentrations (MICs) of RFP were determined by broth microdilution method using Middlebrook 7H9 broth. One hundred and sixty six epidemiologically unrelated M. tuberculosis strains were examined. A total of 99 genetic alterations in the 69 bp core region of rpoB gene were detected in 95 out of 166 strains. Among them, 96 out of 166 strains showed RFP-resistant phenotypes with MICs > or = 2 micrograms/ml. Examination of the correlation between the MICs of RFP and amino acid substitutions in 69 bp core region of rpoB gene revealed that 58 out of 59 strains containing amino acid substitution in codon 531 showed highly RFP-resistant phenotypes with MICs > or = 64 micrograms/ml. In contrast, a variable level of RFP-susceptibility was observed among strains containing amino acid substitutions in either codon 516 or 526. On the other hand, the MICs of three strains with a point mutation in either codon 515 or 533 were all < or = 1 microgram/ml. Our results suggest that rpoB gene sequencing is useful for not only the detection of RFP-resistant M. tuberculosis strains, but also the prediction of RFP-susceptibility of the strains.

Antibiotics, Antitubercular↗
PubMed1997

[Efficacy of erythromycin inhalation in chronic respiratory infection caused by Pseudomonas aeruginosa].

The prognosis of chronic respiratory tract infection with Pseudomonas aeruginosad considered to be poor. However, low-dose and long-term 14 membered macrolide, such as erythromycin or clarithromycin, treatment has been reported as effective clinically in chronic lower respiratory tract disease. There was no report to investigate the effect of macrolide on chronic biofilm related Pseudomonas aeruginosa respiratory tract infection in vivo. In a newly established murine model of chronic Pseudomonas aeruginosa respiratory infection mimicking diffuse panbronchiolitis (DPB), we investigated the effect of erythromcin inhalation on viable bacteria in the lungs. Infection was produced by placement of a plastic tube in the bronchus with inoculating. Pseudomonas aeruginosa suspended in saline was also inoculated in bronchus after intubation of the tube. Viable bacteria were constantly isolated at 10(4) 10(6) cfu-specimen from the lungs for more than 30 days. Treatment with erythromycin inhalation for four days reduced the number of viable bacteria in the lungs with statistically significant. Our result indicated that our new model of chronic respiratory tract infection is simple and provides a useful tool to study the pathogenic process and treatment of such infection. Our results also suggest that the erythromycin inhalation is effective on chronic Pseudomons aeruginosa respiratory infection.

Administration, Inhalation↗
PubMed1997

[Cytomegalovirus retinitis in a patient with systemic lupus erythematosus].

We report a rare case of cytomegalovirus (CMV) retinitis in association with systemic lupus erythematosus (SLE). A 36-year-old female was admitted to our hospital because of nephrotic syndrome and renal insufficiency due to lupus nephritis. After steroid and immunosuppressant treatment for lupus nephritis, she began to complain of floaters and visual disturbance. She was diagnosed as having CMV retinitis based upon the depressed immune status and the clinical appearance of fundus. As soon as CMV retinitis was diagnosed, antiviral treatment with intravenous ganciclovir was instituted and maintained for 7 months. She was treated successfully and almost no progression or relapse of CMV retinitis was documented without ganciclovir maintenance treatment during a 2 year follow-up period. It is suggested that CMV retinitis can occur in patients with SLE treated with steroid and immunosuppressant, indicating the importance of early diagnosis and treatment for CMV retinitis.

Adult↗
PubMed1997

Role of coagulase in a murine model of hematogenous pulmonary infection induced by intravenous injection of Staphylococcus aureus enmeshed in agar beads.

We describe a novel mouse model of acute staphylococcal pneumonia induced by intravenous injection of Staphylococcus aureus enmeshed in agar beads. For comparison, we also used various strains of bacteria, including three strains of S. aureus, two strains of Staphylococcus epidermidis, one strain of Streptococcus pyogenes, three strains of Pseudomonas aeruginosa, and one strain of Klebsiella pneumoniae. All except two strains of S. aureus were cleared rapidly from the lungs. When S. aureus NUMR1 enmeshed in agar beads was injected intravenously, the organisms concentrated and remained in the lung for a period longer than several weeks. Multiple lung abscesses were evident macroscopically, and histological examination of the infected lung showed multiple lung abscesses around the pulmonary arterioles, consisting of bacterial colonies encircled with fibrin filaments and surrounded by inflammatory cells of neutrophils and macrophages. When 14 strains of clinically isolated S. aureus were injected intravenously, the number of bacteria recovered from the lung tissue 7 days after infection correlated with the titer of staphylocoagulase (P < 0.01) but not with the titer of clumping factor. Injection of coagulase-deficient mutant strain DU5843 was associated with a markedly reduced number of viable bacteria isolated from the lung, compared with its coagulase-positive parental strain DU5789. Our results suggest that coagulase may play a role in the development of blood-borne staphylococcal pneumonia in our model. Our animal model is simple and reproducible and resembles blood-borne staphylococcal pneumonia in humans, and it could be useful for investigating the pathogenicity or treatment of staphylococcal pulmonary infection, including infections with methicillin-resistant S. aureus.

Agar↗
PubMed1997

Effect of clarithromycin on lymphocytes in chronic respiratory Pseudomonas aeruginosa infection.

In a newly established murine model of chronic Pseudomonas aeruginosa respiratory infection mimicking diffuse panbronchiolitis (DPB), we investigated the effect of oral administration of clarithromycin on lymphocyte accumulation in the lung. Infection was produced by placement of a plastic tube precoated with P. aeruginosa in the bronchus. The number of bacteria on the tube was 6.25 +/- 0.22 log10 colony-forming units (cfu)/ml. Viable bacteria were constantly isolated at 10(5) to 10(6) cfu/specimen from the lungs for more than 1 yr. The histopathologic features resembled those of DPB consisting of massive accumulation of lymphocytes in the lung. The total number of pulmonary lymphocytes started to increase on Day 7, reaching a peak level within 12 d of intratracheal challenge. The number remained steady at that level for up to 120 d. There was also a steady fall in the CD4+/CD8+ ratio in the lungs, commencing on Day 7 and persisting to Day 120. A 10-d course of oral clarithromycin (10 mg/kg/d) from Day 7 resulted in a reduction of lymphocyte numbers to baseline level, although the dose did not influence the number of bacteria in the lungs. Treatment also increased the CD4+/CD8+ ratio to the baseline level from Day 7 to 17. Our results were similar to those detected in bronchoalveolar lavage fluid of patients with DPB and suggest that the therapeutic benefits of clarithromycin are due to its anti-inflammatory properties rather than antimicrobial effect.

Animals↗
PubMed1997

Rapid prediction of rifampin susceptibility of Mycobacterium tuberculosis.

We evaluated the relationship between rifampin (RIF) susceptiblility and amino acid substitution in rpoB gene of Mycobacterium tuberculosis and the usefulness of rpoB gene sequencing in the rapid prediction of RIF susceptibility of M. tuberculosis in clinical specimens. A total of 76 genetic alterations in the 69 bp core region of rpoB gene were detected in 74 of 130 M. tuberculosis strains. Examination of the correlation between the minimum inhibitory concentrations (MICs) of RIF and amino acid substitutions in the 69 bp core region of rpoB gene revealed that all 43 strains containing amino acid substitution with Leu or Trp in codon 531 showed RIF-resistant phenotypes, with MICs > or = 64 microg/ml. In contrast, a variable level of RIF susceptibility was observed among strains containing amino acid substitutions in either codon 516 or codon 526. In the clinical study, we tested 26 sputum samples, two gastric lavages, and one synovial fluid sample obtained from patients with tuberculosis. The RIF susceptibility predicted by direct rpoB sequencing was satisfactorily compatible with the results of the RIF-susceptibility test and the MICs of RIF against isolated organisms. Our results suggest that rpoB gene sequencing is useful for the detection of M. tuberculosis in clinical samples as well as the rapid prediction of RIF susceptibility of these strains.

Amino Acid Sequence↗
PubMed1997

[Self-expanding nitinol stents for treatment of bilateral main bronchial stenosis caused by esophageal cancer].

A 68-year-old man was admitted because of dyspnea. Nine months earlier, he had undergone radiotherapy for esophageal carcinoma. Chest CT scan obtained on admission showed a tumor shadow behind the tracheal carina. Bronchoscopy revealed that the lower trachea and bilateral main bronchi were compressed from the back and narrowed by the esophageal cancer. To maintain the airway, under fluoroscopic and guide-wire control, a self-expanding nitinol stent (SENS, Accuflex, Microvasive) was implanted in the lower trachea and left main bronchus. At the same time, other SENS was similarly implanted in the lower trachea and right main bronchus. During the implantation, the left nitinol stent was connected to the side of the right nitinol stent to form a T-shape. There was little sputum at the joint portion of the stents and the ventilation of both lungs remained adequate. Severe dyspnea markedly improved after placement of two nitinol stents. Knitted SENS is made of a nickel titanium alloy. SENS was formulated for use in the management of biliary obstruction. However, it is highly flexible and easy to implant. So, it is suitable for the treatment of airway obstruction. Although the implantation of SENS in extensive tracheobronchial stenosis has not previously been reported, it should be useful for prevention of airway obstruction.

Aged↗
PubMed1996

Time trends and survival after operations for primary lung cancer from 1976 through 1990.

To assess the time trends and survivals after operations for primary lung cancer, the cases of 845 consecutive patients who underwent thoracotomy between 1976 and 1990 were retrospectively reviewed by groups corresponding to year of the operation (the early period was 1976 to 1980, n = 208; the middle period was 1981 to 1985, n = 291, and the late period was 1986 to 1990, n = 346). The 5-year survivals at the early, the middle, and the late periods were 31.5%, 39.0%, and 54.0%, respectively, with significant improvement particularly at the late period (p < 0.05 for the early period vs the middle period, p < 0.01 for the early or middle period vs the late period); the improvement was caused by increase in the ratio of patients with stage I disease (20.7% at the early period, 32.0% at the middle period, 44.2% at the late period), increase in the rates of complete tumor resection with lymph node dissection (57.2%, 68.0%, 74.3%, respectively), and decrease in the rates of operation-related death (3.8%, 3.4%, 0.9%, respectively). The postoperative prognosis of patients with stage II disease at the late period (5-year survival 74.8%) showed significant improvement compared with the other periods. Moreover, the prognosis of patients with stage IIIa, pN2 disease (5-year survival 41.5%) showed significant improvement, which was caused by the significant decrease in patients with pT3 N2 M0 disease and poor prognosis.

Adenocarcinoma↗
PubMed1996

A cell-free system of Tn3 transposition and transposition immunity.

BACKGROUND: Tn3 is a bacterial transposon, which encodes transposase required for its transposition. Tn3 has terminal inverted repeat (IR) sequences of 38 bp in length, whose inner region, called the B domain, is bound by transposase. Tn3 confers transposition immunity, a phenomenon in which Tn3 transposes to a target replicon with Tn3 much less frequently than to a target replicon with no Tn3. RESULTS: To understand transposition and transposition immunity at the molecular level, we constructed a cell-free system using a plasmid as the target. Transpositional recombination occurred in a cell extract containing transposase between the target and a donor plasmid carrying mini-Tn3 at a high frequency. The reaction required ATP, Mg2+, dNTPs and 2% polyvinyl alcohol, and was inhibited by inhibitors for DNA synthesis and DNA gyrase. In this system, when a plasmid with the IR sequence was used as the target, the frequency of transposition was significantly decreased, demonstrating that the transposition immunity conferred by Tn3 is reproduced in vitro. Preincubation of the target in the cell extract increased the level of transposition immunity. On the other hand, mutations within the B domain in the IR sequence of the target abolished transposition immunity. CONCLUSIONS: Transposition of Tn3 and transposition immunity could be reproduced in vitro. The results demonstrate that the binding of transposase to domain B of the IR sequence in the target replicon is responsible for transposition immunity. We propose that the transposition immunity results from conversion of the normal synaptic complex formed between the donor and target molecules to another complex which is inactive for transposition, due to the interaction between transposases binding to the IR sequences in the donor and target molecules.

Base Sequence↗
PubMed1996

Specific nicking at the 3' ends of the terminal inverted repeat sequences in transposon Tn3 by transposase and an E. coli protein ACP.

BACKGROUND: Tn3, a bacterial transposon, carries tnpA gene encoding transposase which is essential for its transposition. The transposition of Tn3 has been reproduced in vitro in a cell extract containing transposase by using a plasmid carrying mini-Tn3 as the donor and another plasmid as the target. Transposase has the ability to bind to the 38-bp terminal inverted repeats (IRs) of Tn3. The molecular mechanism of the initiation step of the Tn3 transposition reaction promoted by the transposase has, however, not been understood. RESULTS: We found that nicking occurred efficiently in the cell-free system at each of the 3' ends of the IRs of mini-Tn3 in the closed circular or linear donor molecules. The nicking reaction required transposase and Mg2+, but did not require ATP, an ATP-regenerating system, dNTPs and polyvinyl alcohol, which were the requirements for the transposition reaction. By using the nicking assay employed here, transposase was purified almost to homogeneity. Gel filtration and sedimentation analyses indicate that transposase forms a dimer in a solution containing 0.5 M NaCl. The nicking activity of the purified transposase was weak and was found to be stimulated by a host factor. The nicking stimulation factor was subsequently purified and found to be ACP, an Escherichia coli acyl carrier protein. CONCLUSIONS: Nicking occurred efficiently at the 3' ends of mini-Tn3 in the reaction mixture containing transposase and ACP. ACP is known to act as a factor which modulates enzymes that are involved in several biological processes either in the acylated or unacylated form. ACP may also modulate transposase to initiate the transposition reaction with nicking at the 3' ends of Tn3.

Acyl Carrier Protein↗
PubMed1996

Expression of type IV collagen-degrading metalloproteinases and tissue inhibitors of metalloproteinases in newly established human oral malignant tumor lines.

We have established 11 human oral tumor lines maintained as in subcutaneous xenografts in BALB/c athymic nude mice, and examined their metastatic and invasive characteristics, and expression of type IV collagen-degrading metalloproteinases and their intrinsic inhibitors (TIMPs). These tumor lines have approximately maintained the histological appearance of the parental tumors. Generally, human tumors maintained subcutaneously in nude mice metastasize only very rarely. However, one mesenchymal tumor line, a malignant melanoma designated MTN, was found to metastasize spontaneously to the lung and a lysate of the MTN cells had a high level of type IV collagenolytic activity. Among epithelial tumor lines, SKH, derived from squamous cell carcinoma, showed high expression of TIMP-1 in Northern blotting and had low type IV collagenolytic activity. SN, derived from squamous cell carcinoma, also showed low type IV collagenolytic activity. These two squamous cell carcinoma lines showed a non-invasive growth pattern when they were implanted orthotopically into the tongues of athymic nude mice. By contrast, tumor lines which showed higher type IV collagenolytic activity had a tendency to grow invasively in mouse tongue. These findings suggest that our 11 newly established tumor lines may provide useful systems for studies of tumor biology and therapy.

Adenocarcinoma↗
PubMed1996

Detection of Cryptococcus neoformans gene in patients with pulmonary cryptococcosis.

Pulmonary cryptococcosis was diagnosed by nested PCR. Extraction of DNA was performed by mechanical destruction of the capsules of Cryptococcus neoformans by the glass bead technique. Nested PCR was positive for 4 of 5 culture-positive specimens but negative for 1 culture-positive specimen, 10 culture-negative specimens, and 1 specimen with undetermined culture results.

Base Sequence↗
PubMed1996

[Radiation induced apoptosis in cultured human epithelial tumor cells].

The mode of cell death in cells undergoing mitotic death after irradiation was studied in twenty cancer cell lines of human gastrointestinal origin. Apoptotic cells were observed in all cancer cell lines after irradiation, whereas two fibroblast strains were quite low in apoptosis frequency. The advent of apoptosis depended on the radiation doses and incubation time. Detailed analysis of one of the carcinoma lines, SH101-P4, revealed that G2 phase arrest was maximum at 12 h postirradiation. The cells began to escape G2 arrest by 24 h. Apoptotic cells began to increase at 12 h postirradiation and became maximal from 72 to 96 h. Apoptosis developed in the G1 phase of the cell cycle subsequent to the irradiation. Moreover, the rate of apoptosis of the cells by irradiation did not correlate with p53 gene abnormalities. These results suggest that apoptosis is one of the modes of mitotic death after irradiation.

Apoptosis↗
PubMed1996

[Self-expanding nitinol stents for treatment of tracheobronchial and esophageal stenosis caused by lung cancer].

A 57-year-old man was admitted because of dysphagia. Two year earlier, endoscopic ND-YAG laser treatment had been performed for squamous cell carcinoma of the tracheal carina. The esophagus was compressed and narrowed by invasion of lung cancer. After ballooning, under endoscopic and fluoroscopic control, a self-expanding nitinol stent (SENS, Ultraflex, Microvasive) was implanted in the esophagus. Immediately after esophageal prosthesis implantation, severe dyspnea and stridor developed because of tumor strictures in the left main bronchus. Under fluoroscopic and guide-wire control, SENS (Accuflex, Microvasive) was implanted in the tracheobronchial tree. Dyspnea, dysphagia and stridor were markedly improved after placement of two nitinol stents. Highly flexible, knitted, self-expanding nitinol stent is made of a nickel titanium alloy. Although the implantation of SENS in tracheobronchial stenosis has not previously been reported, it should be useful for prevention of airway obstruction.

Alloys↗
PubMed1996

[Differential diagnosis of tuberculous pleurisy by the measurement of cytokine concentration in pleural effusion].

Pleural fluids obtained from 26 patients with tuberculous pleurisy (T-group), 11 with parapneumonic pleurisy (B-group) and 21 with malignant pleurisy (M-group) were tested for their biologic parameters and cytokine concentrations. 1) The average age of T-group was over 10 years lower than that of M-group with a statistically significant difference. 2) The average CRP value of B-group and the positivity on PPD skin test of T-group were higher than those of the other groups, respectively. 3) Yellowish pleural fluids were mainly observed in T- and B-group, while bloody pleural fluids were mostly seen in M-group with a statistically significant difference. The average total protein amount and adenosine deaminase value in pleural fluid significantly increased in T-group. The percentage of polymorphonuclear leukocytes showed a significant increase in B-group, while lymphocytes significantly increased in T-group with a statistically significant difference. 4) Although no significant difference in concentrations of IL-1 beta, IL-2, IFN-gamma and TNF-alpha in serum was noticed among the three groups, the average concentrations of IFN-gamma and TNF-alpha in pleural fluid in T-group were significantly higher than those in the other groups. 5) TNF-alpha-mRNA of mononuclear cells in pleural fluid was strongly expressed in 3 out of 11 patients of T-group, while no expression was observed in 6 patients of M-group. In conclusion, the measurement of concentrations of two kinds of cytokines in pleural fluid, IFN-gamma and TNF-alpha, may be clinically useful for the differential diagnosis of tuberculous pleurisy from parapneumonic pleurisy and malignant pleurisy.

Adult↗