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Biomedical subjects

Y Kazuyama

Publications and source records attributed to Y Kazuyama.

At least 19 recordsLinked to original sources
PubMed2001

Diagnosis and monitoring of human cytomegalovirus diseases in patients with human immunodeficiency virus infection by use of a real-time PCR assay.

We used a real-time PCR assay to measure human cytomegalovirus (HCMV) DNA load in whole blood and plasma of 70 patients who were infected with human immunodeficiency virus type 1. Break points of 3.0 x 10(3) copies/mL in whole blood and 1.0 x 10(3) copies/mL in plasma were well-correlated with the existence of definite HCMV disease (sensitivity, 93% and 86%; specificity, 89% and 85%; positive predictive value, 70% and 63%; and negative predictive value, 98% and 95%, respectively). In patients with < 50 cells/microL of CD4(+) T lymphocytes, positive predictive values increased to 78% and 71%, respectively. The viral loads of all patients who received anti-HCMV therapy declined to < or =2.0 x 10(2) copies/mL in parallel with the improvement of clinical symptoms. These findings show that the HCMV DNA load quantified with our method is a useful tool for diagnosis of HCMV diseases and for monitoring the disease activity in patients infected with HIV-1.

AIDS-Related Opportunistic Infections↗
PubMed2001

Use of real-time PCR on blood samples for diagnosis of invasive aspergillosis.

We developed a new quantitative system for diagnosis of invasive pulmonary aspergillosis (IPA) using real-time automated polymerase chain reaction (PCR). Intra-assay and interassay precision rates for in vitro examination were 2.53% and 2.20%, respectively, and the linearity of this assay was obtained when there were >20 copies/well. We examined 323 samples taken from 122 patients with hematological malignancies, including 33 patients with IPA and 89 control patients. Blood samples were subjected to PCR antigen detection methods, using enzyme-linked immunosorbent assay (ELISA) and determination of plasma (1-->3)-beta-D-glucan (BDG) concentration. The sensitivities of PCR, ELISA, and BDG measurement for diagnosis of IPA were 79%, 58%, and 67%, respectively; the specificities were 92%, 97%, and 84%. Positive findings on PCR preceded those of computed tomography by -0.3+/-6.6 days, those of BDG measurement by 6.5+/-4.9 days, and those of ELISA by 2.8+/-4.1 days. Real-time PCR was sensitive for IPA diagnosis, and quantitation was accurate.

Adolescent↗
PubMed2000

Donor lymphocyte infusion for treatment of life-threatening respiratory syncytial virus infection following bone marrow transplantation.

We describe two patients who developed respiratory syncytial virus (RSV) pneumonia after BMT. One died of RSV pneumonia after three courses of steroid pulse therapy. Surprisingly, RSV antigen was identified in the bronchoalveolar lavage fluid (BALF) obtained post mortem. Steroid pulse therapy might have suppressed anti-RSV immunity, leading to persistent RSV infection for more than 1 month. The other patient received donor lymphocyte infusions (DLI) for relapsed plasma cell leukemia, while having active RSV pneumonia. His respiratory condition improved after DLI, and RSV antigen disappeared in BALF and nasal swabs. DLI might be effective in cases of life-threatening RSV pneumonia.

Acute Disease↗
PubMed2000

Real-time automated PCR for early diagnosis and monitoring of cytomegalovirus infection after bone marrow transplantation.

The purpose of this study was to assess the usefulness of real-time automated PCR as a quantitative, highly reproducible, and sensitive method to detect cytomegalovirus (CMV) DNA in blood specimens. Intra- and interassay precision rates were 0.89% (small number of copies [L]), 1.43% (middle number of copies [M]), and 1.12% (high number of copies [H]), and 4.46% (L), 1.51% (M), and 2.28% (H), respectively. The linearity of this assay was obtained between 10 and 10(7) copies/well, with a minimum detection limit of 20 copies/well. Specimens from 55 of 70 healthy subjects were found to be positive for CMV antibody, but CMV DNA was not detected in any of them. In the qualitative assessment of each specimen, the results of the CMV antigenemia assay and those of the real-time PCR assay agreed in 80% (plasma specimens), 79% (all nucleated cells), and 86% (blood) of the cases examined. For eight patients diagnosed as having CMV infection or disease, no sample was positive in the antigenemia assay earlier than in the real-time PCR assay. Furthermore, the results of this assay could be obtained within 8 h. We concluded that the real-time PCR assay is useful for rapid diagnosis of CMV infection and monitoring of clinical courses.

Adolescent↗
PubMed1998

Prolonged respiratory failure in chlamydia pneumoniae pneumonia.

We describe a 65-year-old man, who had cardiomyopathy and developed acute respiratory failure requiring ventilator treatment. Acute pneumonia caused by Chlamydia pneumoniae was diagnosed based on PCR positivity of bronchoalveolar lavage. Gas exchange did not improve in response to appropriate antibiotic therapy, and the patient died.

Acute Disease↗
PubMed1997

A novel method for isolation of Chlamydia pneumoniae by treatment with trypsin or EDTA.

To establish a novel method for the efficient isolation of Chlamydia pneumoniae, experiments were performed to determine the effects of EDTA or trypsin treatment of C. pneumoniae on its adsorption and inclusion body formation. Treatment of C. pneumoniae with 0.1% trypsin or 1 mM EDTA significantly increased inclusion body-forming activity from 8,000- to 10,000-fold higher than that of the control. C. pneumoniae was successfully isolated in cultured cells which were inoculated with clinical specimens after treatment with 0.1% trypsin.

Bacteriological Techniques↗
PubMed1993

Prolonged and recurrent tonsillitis associated with sexually transmitted Chlamydia trachomatis.

Chlamydia trachomatis is a common sexually transmitted pathogen. We describe six cases of tonsillitis associated with sexually transmitted C. trachomatis infection. The organism was isolated from tonsillar crypts in all patients, and from uro-genital swabs in five of the six patients. In three partners of the patients, C. trachomatis infection of the uro-genital organ was assessed. They all had a history of orogenital sexual intercourse prior to the illness.

Adult↗
PubMed1993

[Association of Chlamydia pneumoniae infection with otitis media with effusion].

Chlamydia pneumoniae has recently been recognized to cause various human respiratory tract diseases, including pharyngitis, bronchitis and pneumonia. The most common pathogens of respiratory tract infections such as Streptococcus pneumoniae and Haemophilus influenzae are frequently present in middle ear effusions. Therefore, it is possible that C. pneumoniae play a role in otitis media with effusion (OME). Isolation of C. pneumoniae from middle ear aspirates of OME was performed by the culture method using the HeLa 229 or HL cell line. Identification as C. pneumoniae was based on positive staining for inclusions by a species-specific fluorescein-conjugated monoclonal antibody. C. pneumoniae was recovered from 17.8% (13 of 73) of the patients with acute OME, and 7.1% (3 of 42) of those with chronic OME, Moreover, antibodies to C. pneumoniae were measured by the microimmunofluorescence method in 14 patients who yielded the agent, and all of them had detectable antibodies to C. pneumoniae. Evidence of recent or current infection by the organism was found in nine patients on the basis of either on IgM antibody titer of 1:16 or higher, or a four-fold rise in the titer of IgG antibody. The study findings indicate that C. pneumoniae can cause OME and that the organism is a new candidate as an etiological agent of middle ear diseases.

Adolescent↗
PubMed1992

Seroprevalence of Chlamydia pneumoniae infections in otolaryngeal diseases.

We studied the seroprevalence of antibodies to Chlamydia pneumoniae, the third species of chlamydia, in patients with acute infections in otolaryngeal sites. The patients were divided into five diagnostic groups, i.e. sinusitis, otitis media, tonsillitis, laryngitis and bronchitis group. Antibodies were measured by the microimmunofluorescent method. Antibodies confirming past infection with C. pneumoniae were found 46.2 per cent of the patients in the diagnostic groups and 44.7 per cent of the subjects in the control group. The difference between these two groups was not statistically significant. Acute or recent antibodies were detected in 10.5 per cent (2/19) of these patients with sinusitis, 19.2 per cent (10/52) of those with tonsillitis, 23.5 per cent (8/34) of those with otitis media, 18.2 per cent (6/33) of those with laryngitis and 22.8 per cent (13/57) of those with bronchitis, whereas only one member of the control group had acute antibodies. These data suggested that C. pneumoniae is an important and common pathogen of otolaryngeal disease.

Acute Disease↗
PubMed1992

Recovery of Chlamydia pneumoniae, in six patients with otitis media with effusion.

Six cases of otitis media with effusion associated with Chlamydia pneumoniae, a currently recognized respiratory tract pathogen, are presented. The organism was isolated from the middle ear fluids and serological evidence confirmed it as the infectious agent. The study population is small; however, these reports suggest C. pneumoniae as a causative agent of middle ear diseases.

Adult↗
PubMed1992

[An isolation procedure of Chlamydia pneumoniae and Chlamydia trachomatis].

The author devised a method which permits simultaneous isolation and identification of Chlamydia using a slide chamber with 8 wells. Contaminating bacteria were eliminated by filtration with the membrane filter. The procedure allowed isolation of Chlamydia pneumoniae and Chlamydia trachomatis from 11 (10.1%) out of 109 and 10 (9.2%) out of 109 otolaryngologic clinical specimens, respectively. The use of HL cells together with Hela-229 cells had been considered essential to isolate Chlamydia from specimens in this field. The conditions for isolating Chlamydia pneumoniae were similar to those for Chlamydia trachomatis. The slide chamber procedure with membrane filter treated specimens was suitable for simultaneous isolation and culture of various species of Chlamydia and allowed easy differentiation of Chlamydia pneumoniae from Chlamydia trachomatis with identification by the indirect fluorescent-antibody technique. Routine examination of clinical specimens using this procedure should be required in the future in order to better understand chlamydial infections.

Bacteriological Techniques↗
PubMed1992

[Isolation of Chlamydia pneumoniae and antibodies to the agent in patients with acute bronchitis].

Isolation of Chlamydia pneumoniae and serologic tests were performed on 85 children and adults patients with acute bronchitis admitted to the Kitasato Institute Hospital from January 1989 to May 1991. C. pneumoniae was isolated from sputa or tonsillar swabs in 11 of 57 (19%) patients examined. Of these, 10 patients were tested serologically and 9 (90%) had 16 or higher titer of IgG antibody. A total of 68 patients were tested serologically, and 17 (25%) revealed positive; 14 had a fourfold rise or more in the titer of IgG antibody, or IgM titer of 16 or more, and 3 had IgG antibody with a titer of 512 or greater. In 34 patients, sera were tested for evidence of acute infections not only with C. pneumoniae, but also with Mycoplasma pneumoniae, influenza A virus, influenza B virus, adenovirus, respiratory syncytial virus, coxackie A9 virus, parainfluenza virus type I, II, and III. Two of the 34 patients were associated with influenza A virus, 4 with influenza B virus, whereas 6 were associated with C. pneumoniae. The data available suggest that C. pneumoniae cause bronchitis much more than has been suspected, and also confirm earlier suggestions that the agent played an important role in respiratory tract infections. Chlamydia trachomatis was recovered from sputa and tonsillar swabs in 6 adults patients with acute bronchitis. Studies are needed for a better understanding of the epidemiology and clinical relevance of this microorganism to lower respiratory tract diseases in adults.

Adolescent↗
PubMed1992

[The pathogenic role of Chlamydia trachomatis in otitis media with effusion].

There are conflicting views concerning middle ear infections due to Chlamydia trachomatis. To ascertain the etiological role of this agent in otitis media with effusion, middle ear effusions were cultured for C. trachomatis and other bacterial flora. A total of 102 patients with otitis media with effusion (OME) were recruited for this study. The study population included 66 patients with acute OME (AOME) and 36 patients with chronic OME (COME). As Chlamydia pneumoniae, the third species of Chlamydia, is also known to be isolated from middle ear effusion of OME, the fluorescent-antibody technique using anti-C. pneumoniae or anti-C. trachomatis antibodies was employed in order to identify the inclusion bodies isolated on HeLa 229 cells as C. trachomatis. C. trachomatis was recovered from 7 patients (10.6%) with AOME and from 8 (22.2%) patients with COME. Bacteria were cultured from 20 of 63 patients with AOME and from 13 of 28 patients with COME. Pathological bacteria were cultured from only 2 patients with C. trachomatis infection in the middle ear. Only normal skin flora, no bacterial pathogens, were isolated from the remainder. Antibodies to C. trachomatis in serum were measured by a microimmunofluorescent method in 13 patients with C. trachomatis infection in the middle ear. Antichlamydial antibody of the IgG type was detected in 84.6% (11/13) of these patients. These results suggest that C. trachomatis causes middle ear infections and plays an etiological role in the pathogenesis of otitis media with effusion.

Adolescent↗
PubMed1991

Malignant lymphomas in Japanese AIDS patients.

Seven non-Hodgkin's malignant lymphomas (MLs) were found in 25 Japanese AIDS (acquired immune deficiency syndrome) patients who died at two hospitals in Tokyo. All of these MLs originated from extranodal organs including the brain (three cases), skin (two cases) liver and adrenal gland. B cell markers were demonstrated in all of them. Epstein-Barr virus (EBV) capsid antigen (EBVCA) was demonstrated in 5/7, nuclear antigen (EBNA) in 2/2, the W fragment of EBV DNA by in situ hybridization in 5/7 and the same fragment by PCR in 6/7, indicating high association of these MLs with EBV. The adult T cell leukemia/lymphoma (ATL), endemic in south-west Japan and known to have a high association with HTLV-I, was not found in this series. The incidence of ML among the present AIDS cases is higher than in any other autopsy reports from western countries, although statistical analysis did not show this to be significant in comparison to some of these reports at a level of p less than 0.05. In spite of apparent higher incidence, the histopathologic and immunophenotypic characteristics of AIDS-associated MLs in Japan are in accordance with those in western countries.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Acute upper respiratory tract infections associated with Chlamydia pneumoniae].

From March 1990 to January 1991, a total of 46 outpatients with acute upper respiratory infections (URTI) were studied to determine the etiological role of Chlamydia pneumoniae. Sera from 40 patients were tested by micro-IF method for evidence of recent or past infections of this organism, and swab specimens from tonsilar crypt from 26 were cultured. Sera from 20 patients without any evidence of acute infectious disease were selected as controls. The seroprevalence of antibodies to C. pneumoniae was 52.5% in patients group and 30.0% in the control group. No statistical difference was found in seroprevalence between patients and controls. Serological evidence of acute infections with C. pneumoniae was found in 7 (17.5%) patients with acute URTI, but was not found in any of the control group. Of 26 patients, three (11.5%) had C. pneumoniae isolated from a tonsilar crypt swab specimen. Therefore ten of the 46 patients with acute URTI were associated with C. pneumoniae. It is suggested that C. pneumoniae is a common pathogen in acute upper respiratory infections without any evidence of lower respiratory tract symptoms.

Acute Disease↗