Biomedical subjects

Masayoshi Negishi

Publications and source records attributed to Masayoshi Negishi.

5 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↗

PubMed2004

A female patient with malarial nephropathy.

Malaria remains one of the world's major health problems, particularly in developing tropical countries. Imported malaria is reportedly increasing in Western countries. Acute renal failure (ARF) is the most common cause of death in severe malaria. We report the case of a 63-year-old female patient with a history of travel to a rural area in South Africa who was in coma and had a high fever on admission. Thirty percent of her erythrocytes were infected with Plasmodium falciparum. She had cerebral malaria, malarial nephropathy, anemia, hepatic dysfunction, and disseminated intravenous coagulation (DIC). Quinine and artesunate treatment decreased the number of parasites in the blood. To manage renal failure, hemodialysis was performed for 11 days. A relationship between ARF and hepatic dysfunction was suggested. This relationship is an indication of the clinical course of the disease. In this article, we discuss the mechanism underlying the development of malarial nephropathy and its management, particularly the usefulness of hemodialysis.

Animals↗

PubMed2003

Differential prevalence of HIV type 1 subtype B and CRF01_AE among different sexual transmission groups in Tokyo, Japan, as revealed by subtype-specific PCR.

We determined the subtype of HIV-1 in 89 infected individuals attending three reference hospitals located in the Tokyo metropolitan area of Japan. Subtyping was performed with subtype-specific polymerase chain re-action (PCR) distinguishing subtype A, B, C, and CRF01_AE and/or phylogenetic analysis of HIV-1 env C2V3C3 sequences. Subtype-specific PCR provided unequivocal results in 97% of samples. Sixty-five subjects were infected with subtype B, 16 with CRFO1_AE, 4 with subtype A, 1 with CRF02_AG, and 3 with subtype C. Among 31 Japanese individuals infected through heterosexual contact, 13 were infected with subtype Band 12 with CRFO1_AE. All of the 41 Japanese men infected through homosexual contact harbored subtype B. These results indicate that subtype B is exclusively predominant in a homosexually transmitted group, whereas subtype B and CRFO1_AE are evenly predominant in a heterosexually transmitted group.

Female↗

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↗