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Atsushi Ajisawa

Publications and source records attributed to Atsushi Ajisawa.

8 recordsLinked to original sources
PubMed2006

Decrease in Epstein-Barr virus-positive AIDS-related lymphoma in the era of highly active antiretroviral therapy.

Recent introduction of highly active antiretroviral therapy (HAART) is reported to have reduced the incidence of lymphoma among HIV-infected individuals. A clinicopathological study was performed on 86 AIDS-related lymphoma patients who were treated in Tokyo area from 1987 to 2005. The incidence of lymphoma detected by autopsy was 27% (53 cases/198 autopsies). Diffuse large B cell lymphoma was the most predominant histological subtype throughout the period (78%). Burkitt's lymphoma (BL) increased from 2% in the pre-HAART era (before end-1997) to 13% in the HAART era, whereas incidence of BL did not vary between HAART users and non-users. Epstein-Barr virus (EBV)-positive lymphoma decreased from 88% in the pre-HAART era to 58% in the HAART era, but did not differ significantly between HAART users (73%) and non-users (74%). Nodal involvement of lymphoma increased from 14% in the pre-HAART era to 50% in the HAART era; however, central nervous system involvement decreased from 62 to 38%. Kaposi's sarcoma-associated herpesvirus infection was rare (4%) among all cases. These data suggest that HAART might play a partial role in these changes, and the alteration in immunological backgrounds, such as EBV prevalence, is suggested as another leading cause of these changes in Japanese AIDS-related lymphoma.

Adolescent↗
PubMed2006

Clinical features of 62 imported cases of dengue fever in Japan.

To describe the clinical features of dengue cases in Japan, a retrospective study was conducted on 62 laboratory-confirmed Japanese dengue cases presented to Tokyo Metropolitan Komagome Hospital between 1985 and 2000. Age distribution was from 18 to 62 years old (mean, 31.5 years). All cases were imported from abroad and diagnosed as dengue fever. Clinical manifestations included fever (100%), headache (90%), and skin rash (82%). Laboratory examinations revealed leukocytopenia (71%), thrombocytopenia (57%), elevated levels of serum aspartate aminotransferase (78%), and lactate dehydrogenase (71%). Antibody responses were consistent with that of secondary flavivirus infection in 60% of cases. Severity of symptoms in patients with primary dengue antibody response and those with secondary flavivirus antibody responses didn't show statistical significance. Dengue virus infection should be taken into consideration in the differential diagnosis of febrile patients who recently entered Japan from tropical or subtropical countries.

Adolescent↗
PubMed2005

Characterization of seven genotypes (A to E, G and H) of hepatitis B virus recovered from Japanese patients infected with human immunodeficiency virus type 1.

To investigate the prevalence of hepatitis B virus (HBV) genotypes and characteristics of HBV isolates among Japanese patients infected with human immunodeficiency virus type 1 (HIV), serum samples collected between September 1990 and March 2002 from 471 HIV-infected patients (age, 38.8 +/- 11.4 [mean +/- standard deviation] years; male, 90%) were tested for hepatitis B surface antigen (HBsAg) and HBV DNA. Positivity for HBsAg and HBV DNA was seen in 42 patients (8.9%), 41 of whom had contracted HIV infection through sexual activity and 1 had hemophilia. Genotypes of HBV were determined by comparative and phylogenetic analyses of the S gene sequence (396 nucleotides [nt]). The distribution of HBV genotypes among the 42 HBV-viremic patients was: A (50%), B (5%), C (24%), D (5%), E (2%), H (10%), A plus D (2%), A plus G (2%). The hemophilia patient had HBV genotype D. Genotypes E, G, and H which had not been reported in Japan, were found in one patient each who had traveled to Zambia, the US, and South America, respectively. Genotypes A and D, which are rare in Japan, were found in patients who had no history of traveling abroad. The entire genome of the HB-JI411 (genotype E [3,212 nt]), HB-JI444G (genotype G [3,248 nt]), and HB-JI260 (genotype H [3,218 nt]) isolates had the highest identity of 98.3%, 99.9%, and 98.5%, respectively, with reported HBV isolates of the same genotype. Most Japanese patients coinfected with HIV and HBV had HBV genotypes that are found rarely or had not been reported in Japan.

Adult↗
PubMed2005

Survey of human immunodeficiency virus (HIV)-seropositive patients with mycobacterial infection in Japan.

OBJECTIVE: To assess DNA polymorphisms in mycobacterial isolates obtained from human immunodeficiency virus (HIV)-seropositive patients with tuberculosis in Japan from 1996 to 2003. METHODS: Restriction fragment length polymorphisms (RFLP) from Mycobacterium tuberculosis and Mycobacterium avium isolates obtained from individual seropositive patients with tuberculosis (n=78) were analysed with the use of IS6110 and (CGG)(5) or IS1245 and IS1311, respectively, as markers. As a control, the same procedures were applied to isolates from HIV-seronegative tuberculosis patients (n=87). RESULTS: Of 86 mycobacterial strains, M. tuberculosis, M. avium and Mycobacterium chelonae were identified in 48 (55.8%), 36 (41.9%) and 2 (2.3%) isolates, respectively. The obtained RFLP patterns of M. tuberculosis isolates from both the HIV-seropositive and -seronegative groups were variable, suggesting no obvious clustering among the isolates. Similar results were obtained in isolates of M. avium. CONCLUSIONS: This is the first report on the molecular epidemiology of Mycobacterium spp. isolated from HIV-seropositive patients in Japan. The results indicate that no particular clones of M. tuberculosis or M. avium prevail in HIV-seropositive patients in Japan. Further monitoring of mycobacterial infection associated with HIV infection in Japan should be continued.

Adolescent↗
PubMed2003

Molecular analysis of human herpesvirus 8 by using single nucleotide polymorphisms in open reading frame 26.

Human herpesvirus 8 (HHV-8) can be classified into distinct subtypes on the basis of sequence polymorphisms in several open reading frames (ORFs). We analyzed the subtypes of HHV-8 in 59 human immunodeficiency virus-infected Japanese patients by using polymorphisms in ORF26 and found that over two-thirds of the HHV-8 isolates fell into major subtype A. We also found that single nucleotide polymorphisms (SNPs) at nucleotide positions 1032 (C-to-A substitution) and 1055 (G-to-T substitution) in HHV-8 ORF26 were correlated with increased susceptibility to Kaposi's sarcoma, compared to the results obtained with HHV-8 with wild-type nucleotides at these positions (P = 0.0106). This observation suggests that molecular heterogeneity of the HHV-8 genome affects the biological properties of HHV-8, resulting in different clinical phenotypes of HHV-8 infection. Since sensitive PCR of ORF26 allowed us to analyze the SNPs by using peripheral blood from HHV-8-infected patients, the ORF26 SNPs will be a potent tool for investigating the pathogenesis of HHV-8 infection.

AIDS-Related Opportunistic Infections↗
PubMed2002

[Cyclosporiasis: four case reports with a review of the literature].

Four patients infected with Cyclospora cayetanensis who sought medical care at the Tokyo Metropolitan Komagome Hospital are herein presented. All were Japanese males, and their ages ranged from 22 to 50 years of age. One patient, who was HIV-positive with a CD4+ lymphocyte count of 141/microliter, demonstrated no AIDS-defining illness. This patient acquired HIV in some Southeast Asian country/countries through heterosexual contact. This patient presented with watery diarrhea with a frequency of up to 18 times a day for more than two months. The other three cases were not considered to be debilitated hosts. Diarrhea occurring from one to ten times a day continued for 6 to 26 days in all of these three patients. The presumed origin of the infection was considered to be Southeast Asian countries and the season of onset of diarrhea was March to July in all four cases. Treatment with a sulfamethoxazole/trimethoprim compound was performed for both the HIV-infected patient and the other non-debilitated patient. Both symptomatic and parasitologic improvements were quickly observed in these patients. A prospective study was performed using fecal specimens from the diarrheal patients to identify the presence of C. cayetanensis during the period from 1996 to 2001. Protozoa-positive specimens were found in 3 of 410 (0.7%) specimens from patients who had traveled overseas, is one of 148 (0.7%) for HIV-infected (the C. cayetanensis-positive patient also acquired the protozoa in Southeast Asia), and in none of 513 (0%) patients who developed diarrhea in Japan. In summary, C. cayetanensis infection is rare in Japan and most patients infected with this pathogen tend to be overseas travelers and HIV-infected individuals at present.

Adult↗
PubMed2002

[Salvage therapy in HIV disease].

Highly active antiretroviral treatment(HAART) is very effective for Japanese Human immunodeficiency virus(HIV) patients in the morbidity and mortality. But the need for salvage therapy is related to the imperfection of current antiretroviral therapy. HIV-RNA load will be detectable in approximately 40% of non-naive HIV patients who are taking triple therapy after 1 year of follow-up. Treatment failure may be related to poor adherence, resistant virus and poor pharmacological bioavailability. This article aims at describing the strategic thoughts in rapid development of pathophysiological as well as clinical and drug-related knowledge. Patient commitment, physician knowledge and an informed supportive environment are important to success in salvage therapy.

Anti-HIV Agents↗