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Y Higashiyama

Publications and source records attributed to Y Higashiyama.

36 records · Page 2Linked to original sources
PubMed1994

Altered expression of a novel cellular gene as a consequence of integration of human T cell lymphotropic virus type 1.

By analysing a genomic DNA clone derived from the human T cell lymphotropic virus type 1 (HTLV-1)-infected cell line, TL-Su, we found that an integrated HTLV-1 provirus interrupted the poly(A) signal-containing exon of a novel gene, RY-1. Nucleotide sequence analysis of a cDNA derived from Jurkat cells revealed that the normal RY-1 mRNA could encode a novel protein that has an unique primary structure, suggesting that a nucleic acid binding property was involved. Proviral integration led to an accumulation of aberrant RY-1 mRNA species in the cells. All the aberrant RY-1 cDNAs derived from TL-Su cells terminated at the poly(A) site of the R region of the HTLV-1 long terminal repeat and initiated in the intron, approx. 800 bp upstream from the putative second exon. Furthermore, another intron, downstream from this position, remained unspliced in some of the cDNAs. In addition to the activation by the integrated viral elements of cryptic promoters located upstream, mechanisms involving altered rates of degradation or transport from the nucleus to the cytoplasm of intron-containing RNA were suggested.

Amino Acid Sequence↗
PubMed1994

Expression of human T lymphotropic virus type 1 (HTLV-1) tax/rex gene in fresh bronchoalveolar lavage cells of HTLV-1-infected individuals.

Accumulating evidence has suggested the involvement of HTLV-1 in the inflammatory lesions of various organs, including the lung. However, the causal relationship between HTLV-1 and inflammatory responses in the organs remains to be elucidated. In order to evaluate the expression of HTLV-1 and its effects in the lung, we examined the expression of mRNA for the HTLV-1 tax/rex gene in fresh bronchoalveolar lavage cells (BALC) and peripheral blood mononuclear cells (PBMC) of 23 seropositive individuals, including six patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), by use of an improved method of reverse transcription-polymerase chain reaction (RT-PCR). The tax/rex mRNA was more frequently detected in BALC than in PBMC. All the HAM/TSP patients and eight of 17 carriers without neurological symptoms showed the expression of tax/rex mRNA in the BALC. IgM class antibodies to HTLV-1 were preferentially detected in sera of the tax/rex mRNA-positive individuals. The detection of tax/rex mRNA correlated closely with the presence of lymphocytosis accompanied by an elevated proportion of IL-2 receptor-bearing T cells in the BALC. Our findings indicate the crucial role of viral expression in the inflammatory response in the lung in HTLV-1-infected individuals.

Adolescent↗
PubMed1994

[Rapid identification of mycobacteria by combined method of polymerase chain reaction and the gen-probe DNA hybridization system].

We developed the rapid detection and identification method of mycobacteria, involving amplification of mycobacterial 16S rRNA gene by nested PCR and identification of M. tuberculosis complex or M. avium-intracellulare complex (MAC) by hybridization protection assay (HPA) using the acridinium-ester (AE) labeled DNA probe. The specificity of the nested PCR combined with DNA probe test was excellent in terms of detection of mycobacterial organisms and identification of M. tuberculosis or MAC. The detection limits of the present method were 10 fg DNA for M. tuberculosis, and 100 fg DNA for MAC, respectively. We further investigated on the optimum temperature for hybridization in HPA with AE labeled DNA probe because there was the difference in the mode of DNA-RNA hybridization from that of DNA-DNA hybridization. In our method, the optimum temperature of hybridization was estimated as 55 +/- 1 degrees C. In preliminary experiments on two clinical cases, we practically detected and identified M. tuberculosis and MAC in clinical specimens, such as sputa, by using this newly devised method. We concluded that this method is useful for rapid detection and identification of M. tuberculosis and MAC in clinical specimens.

Adult↗
PubMed1994

[Evaluation for rapid detection of rifampicin-resistant mycobacterium tuberculosis by polymerase chain reaction-single strand conformation polymorphism].

We evaluated usefulness of the rapid diagnostic method for detection of rifampicin (RFP)-resistant Mycobacterium tuberculosis, which was based on polymerase chain reaction. The MICs of RFP were measured for 38 clinical isolates of Mycobacterium tuberculosis which were suspected to be RFP-resistant organisms, and 12 strains were found to be resistant to RFP. The PCR primers used were the same as those reported by Telenti et al, which were targeting the RNA polymerase beta subunit gene (rpoB). We confirmed that this gene was possessed by all the strains tested. Eight strains out of the 12 strains with RFP-resistant phenotype were demonstrated to have a point mutation or some alterationin the rpoB gene on the basis of PCR-single strand conformation polymorphism (SSCP). Thus, the sensitivity of our method was calculated as 67%. In addition, we could not detect any alterations in the rpoB gene by all RFP-susceptible strains. These results indicated that rapid detection of the RFP-resistant Mycobacterium tuberculosis was possible directly from clinical specimens by using PCR-SSCP technique.

Base Sequence↗
PubMed1994

[Association between diffuse panbronchiolitis and HTLV-I infection].

To determine whether HTLV-I infection is associated with diffuse panbronchiolitis (DPB), we investigated T-cell surface markers of peripheral blood and bronchoalveolar lavage fluid (BALF) in 9 healthy volunteers, 6 HTLV-I seronegative DPB patients (HTLV-I(-)DPB) and 8 HTLV-I seropositive DPB patients (HTLV-I(+)DPB). In peripheral blood, no significant difference was observed between HTLV-I(-)DBP and healthy volunteers. However, in BALF, HTLV-I(-)DPB showed a significant decrease of the CD4/CD8 ratio and an increase of CD8+HLA-DR+ cells compared with healthy volunteers. CD3+CD25+ and CD4+HLA-DR+ cells in peripheral blood were significantly increased in HTLV-I(+)DPB compared with those in HTLV-I(-)DPB. No significant difference was observed in BALF cells between HTLV-I(-) and HTLV-I(+)DPB with the exception of CD3+CD25+ cells. The most striking result was a marked elevation of CD3+CD25+ cells in 2 of 8 HTLV-I seropositive patients. Microscopic findings of open lung biopsy specimens obtained from the 2 patients differed from the typical microscopic findings in DPB. From these findings, we consider that HTLV-I infection may be associated with pulmonary lesions like DPB, but of a different, pathologically distinct, type.

Adult↗
PubMed1993

[Detection of mecA gene of methicillin resistant staphylococci from oral swabs by polymerase chain reaction].

We evaluated the polymerase chain reaction method (PCR) for the rapid detection of methicillin resistant Staphylococcus aureus (MRSA), and compared it with the conventional culture method. Primers for amplification of mecA gene were synthesized by DNA synthesizer according to the published sequences of mecA gene. The results were as follows: Specificity of PCR was excellent, as there was no cross-reaction with any organism other than MRSA. Fifty colony forming units of MRSA were detected, indicating good sensitivity. We examined oral swabs from 13 bed-ridden patients (age range: 65-82 yrs) by PCR and the conventional culture method. The PCR elicited positive results in 6 out of 13 cases. MRSA or coagulase negative Staphylococci (CNS) in Mueller-Hinton agar containing 12.5 micrograms/ml methicillin were obtained from all of these PCR-positive specimens. Two of 7 PCR-negative specimens raised MRSA or CNS colonies, but the number of colonies from these specimens was below the sensitivity threshold of the PCR. The good specificity and sensitivity of the PCR method for the detection of mecA gene obtained in this study suggest the possibility of application of this method for detection of MRSA in clinical specimens.

Aged↗
PubMed1992

[Antigen detection in the murine models of systemic candidiasis].

We compared two latex agglutination tests for serum candidal antigen in murine models of systemic infection and gastrointestinal colonization. In the intravascular-infection model, mannan detection test was positive at 2 hours after inoculation, but Cand-Tec was less sensitive than mannan detection test in this model. In the gastrointestinal colonization model followed by systemic infection in neutropenic mice, the mannan antigen test became positive after 3 weeks of colonization with increased number of Candida of the stool, and Cand-Tec became positive after 5 weeks in neutropenic mice.

Animals↗
PubMed1992

[Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum].

Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum were reported. The first two patients developed pneumonia with Corynebacterium pseudodiphtheriticum during steroid therapy used against their underlying diseases. The other two patients had acute exacerbation of chronic pulmonary diseases caused by C. pseudodiphtheriticum. These four patients improved by antibiotic therapy. Though nondiphtheria corynebacteria are regarded as "normal flora" when they are isolated from sputum, they should be recognized as potential pathogens.

Aged↗
PubMed1992

An outbreak of Legionnaires' pneumonia in a nursing home.

An outbreak of Legionnaires' pneumonia occurred at a nursing home in December 1990. A 79-year-old female and a 73-year-old male clerk who were staying at the nursing home developed pneumonia with only a 5-day interval. Legionella pneumophila serogroup I was isolated from transtracheal aspirate of the former and sputum of the latter. After treatment with a combination of erythromycin and rifampicin both patients improved. Serological surveillance of inpatients and staff of the nursing home was performed in February 1991. Seven out of 51 samples (14.0%) showed a titer higher than 1:128 of anti-Legionella pneumophila serogroup I antibody determined by indirect immunofluorescence; two of these seven complained of respiratory symptoms. Molecular epidemiology analyzed by restriction endonuclease digestion of isolated L. pneumophila showed an identical pattern which suggested a common origin.

Aged↗
PubMed1992

Fatal pneumonia caused by Corynebacterium group JK after treatment of Staphylococcus aureus pneumonia.

A 76-year-old man who was admitted to the hospital because of chronic renal insufficiency and chronic hepatitis died of Corynebacterium group JK pneumonia, after showing a slight improvement by treatment of Staphylococcus aureus with sulbactam/cefoperazone and minocycline. Transtracheal aspiration (TTA) just before his death revealed numerous gram-positive bacilli phagocytized by many neutrophils and more than 10(8) colony forming units (CFU)/ml of Corynebacterium group JK. A drug susceptibility test showed Corynebacterium group JK was resistant to many antibiotics, with the exception of vancomycin and amikacin.

Aged↗
PubMed1992

[Epidemiology of HTLV-I carriers in Hirado Island and virological and immunological investigation of HTLV-I associated pulmonary disease].

Adult T-cell leukemia (ATL) is endemic in Kyushu. Our study at Hirado island in Nagasaki prefecture revealed a higher incidence (35.9%) of HTLV-I carriers in villages with fishing than in those without (16.5%). HTLV-I carriers showed a higher incidence of abnormal findings on chest roentgenogram (21.7%) than non-carriers (16.5%), but most were lesions of old pulmonary tuberculosis and pleural thickening. Virological and immunological investigations were performed for 10 HTLV-I carriers, 3 patients with HTLV-I associated myelopathy (HAM), and 3 patients with ATL to determine the presence of HTLV-I associated pulmonary disease. In HAM patients, there were high titers of anti HTLV-I antibody, positive IgA reaction to HTLV-I, and an increase in interleukin-2 receptor (IL-2)-positive T-cells in the peripheral blood; and lymphocytosis and an increase in IL-2-positive T-cells in the bronchoalveolar lavage fluid (BALF). Virological examination showed the presence of pX gene and tax1/rex1 mRNA in the peripheral blood and BALF. Similar immunological and virological findings in 2 of 10 carriers suggested the presence of HTLV-I associated pulmonary disease.

Aged↗
PubMed1991

[Bacteriological studies on pharyngeal and tracheal colonization in patients of operations and patients in ICU].

Bacterial colonization of the pharynx before and one week after operation, and contamination of the trachea during intubation in 7 patients who underwent operations were investigated. And bacterial colonization of pharynx, tracheas, and mechanical-ventilators in 7 ICU patients was investigated. Flora of palms of 10 ICU personnel was also examined: 1) Oral bacteria began to be found in the trachea several hours after intubation. 2) In oropharyngeal flora, one week after operation, Neisseria and anaerobes which belong to normal flora decreased because of antibiotics, but no new resistant bacteria appeared. 3) Although isolates from pharynx of preoperative patients were normal flora, those of ICU patients were Staphylococcus epidermidis, Enterococcus spp., gram-negative rods such as Pseudomonas aeruginosa, and yeast liked organisms etc, which were resistant to antibiotics. 4) From the trachea of intubated patients in ICU, oral bacteria were isolated. 5) Pseudomonas pickettii was isolated from the expiratory side of ventilator circuits in one patient, but it was not isolated from the patient. 6) From hands of ICU personnel, gram-positive bacteria such as coagulase negative staphylococci, Coryne bacterium spp. and Bacillus spp. were isolated. 7) One patient in ICU, who developed pneumonia due to resistant Bacteroides fragilis following oropharyngeal colonization, was reported. These studies suggested the importance of environmental control, careful selection of antibiotics, and attention to change of flora.

Aged↗
PubMed1991

[The comparison of drug susceptibility of antituberculous agents against colonizing M. intracellulare and infectious M. intracellulare].

The susceptibility of antituberculous agents against colonized M. intracellulare which were isolated from patients with pulmonary disease and infectious M. intracellulare (pathogens) isolated from atypical mycobacterial culture was investigated. Aminoglycosides were more potent against colonized organisms than against pathogens. Isoniazid, ethambutol and rifampicin showed less potent antimicrobial activity against both colonized organism and pathogens as compared to aminoglycosides. On the contrary susceptibility of cycloserine against colonized organisms was as potent as against pathogens.

Aged↗