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Biomedical subjects

A Ajisawa

Publications and source records attributed to A Ajisawa.

At least 19 recordsLinked to original sources

Quantitative and qualitative abnormalities in HIV-1-specific T cells.

OBJECTIVE: To assess the characteristics of CD4 and CD8 T cells specific for HIV-1 and cytomegalovirus (CMV) antigens in untreated and treated HIV-1-infected patients. METHODS: Antigen-specific T cell frequencies were determined by flow cytometric detection of antigen-induced intracellular cytokines. RESULTS: In untreated patients, HIV-1-specific CD4 T cell counts in peripheral blood were less than one tenth of CMV-specific CD4 T cell counts, while the number of specific CD8 T cells was approximately the same for both HIV-1 and CMV. In patients treated with highly active antiretroviral therapy (HAART) for less than 1.5 years, HIV-1-specific CD4 and CD8T cell counts were significantly lower than those in untreated patients. Perforin expression in HIV-1-specific CD8 T cells was significantly lower than that in CMV-specific CD8 T cells. CONCLUSION: These data indicate that HIV-1-specific T cells in HIV-1-infected patients have quantitative and qualitative abnormalities.

Adult↗

Inverse relationship between the titre of TT virus DNA and the CD4 cell count in patients infected with HIV.

OBJECTIVES: To investigate the prevalence and relative titre of TT virus (TTV) DNA, and to examine the relationship between the extent of TTV viraemia and the immune status among 144 patients with HIV infection; 178 age- and sex-matched healthy individuals were also studied. METHODS: TTV DNA was detected quantitatively by two distinct polymerase chain reaction (PCR) methods [untranslated region (UTR) and N22]. UTR PCR detects all TTV genotypes, and N22 PCR can primarily detect four major TTV genotypes (1-4). RESULTS: Using UTR PCR and N22 PCR, respectively, TTV DNA was detected significantly more frequently in HIV-infected patients than in controls (99 versus 91%, P < 0.001; 56 versus 27%, P < 0.0001), and the relative titre (10N/ml) was significantly higher in HIV-infected patients [4.5 +/- 1.2 (mean +/- SD) versus 3.1 +/- 0.9, P < 0.0001; 2.6 +/- 1.5 versus 1.5 +/- 0.9, P < 0.0001]. Age, sex, co-infection with hepatitis B or C virus, and risk factors for HIV transmission did not appear to be significant factors associated with the titre of TTV viraemia. However, the titre of TTV DNA was significantly higher in HIV-infected patients with AIDS (P < 0.0001), those with low CD4 T cell count (P < 0.0001), or those with high HIV viral loads (P = 0.0047). CONCLUSION: TTV is highly prevalent and high-titred in HIV-infected patients. The TTV viral load may reflect the degree of immune status of these immunocompromised hosts.

AIDS-Related Opportunistic Infections↗

[Two cases of typhoid fever with reduced susceptibility to fluoroquinolones].

Two separate febrile Indian patients who reside in Japan and had recently returned from their country were diagnosed as suffering from typhoid fever. Fluoroquinolone therapy was clinically ineffective and the addition of a third-generation cephalosporin was required in each case. Each strain of Salmonella Typhi was resistant to nalidixic acid in vitro and also showed higher minimal inhibitory concentration to other quinolones than usual susceptible strains. Similar cases of typhoid fever responding poorly to quinolone treatment have been observed in the Indian subcontinent, south-east Asia and central Asia since the early 1990s, and potential spread by travelers into Japan is of serious concern. Although quinolones still remain the drugs of choice for treatment of typhoid fever, physicians should be aware of the possibility and implications of clinical treatment failure.

Adult↗

A new polymorphism in the promoter region of the human interleukin-16 (IL-16) gene.

Interleukin 16 (IL-16) is a chemotactic cytokine which binds to CD4 and affects T cell activation. Here we report a novel single nucleotide polymorphism, T to C, in the promoter region of the IL-16 gene in two distinct Asian populations, Japanese and Thai. This mutation occurs at an allele frequency of approximately 22% and 18%, respectively. Although IL-16 potently suppresses replication of human immunodeficiency virus type 1 (HIV-1), we observed no significant difference in the allele frequency of this polymorphism between HIV-1-infected and non-HIV-1-infected individuals in both Asian populations. Since differential IL-16 levels have been reported to be associated with inflammatory diseases such as systemic lupus erythematosus, atopic dermatitis and allergic asthma, it would be of interest to analyze the allele frequency of this mutation in patients with these autoimmune and allergic diseases.

Gene Frequency↗

Clinical and bacteriological profiles of patients with typhoid fever treated during 1975-1998 in the Tokyo Metropolitan Komagome Hospital.

Patients with typhoid fever presenting to the Tokyo Metropolitan Komagome Hospital during the period 1975-1998 were retrospectively investigated. All cases were diagnosed by a positive culture for Salmonella typhi in either of their clinical specimens. Of the total number of 130 patients, 57% contracted the disease abroad; this population increased in later years as the total numbers of cases decreased. The period from disease onset to diagnosis averaged 14 days with 20% of the cases requiring over three weeks to establish a diagnosis. As for symptomatology relative bradycardia was seen in less than half of the cases, and rose spots or splenomegaly in less than one third. A positive blood culture was the most frequent test establishing the diagnosis followed by a positive stool culture. Intestinal bleeding was recognized in as many as 35 cases (27%) and even intestinal perforation occurred in two cases (1.5%). Chloramphenicol was most commonly employed during the early study period, however, during the late period it was replaced by fluoroquinolones. The clinical cure rate was 98% with regimens that include fluoroquinolones/quinolone; however it was 87% with the other antimicrobial regimens. Bacteriological relapse occurred in 25% of the non-fluoroquinolone group while only in 2.0% in the fluoroquinolone/quinolone group. Four strains of Salmonella typhi that were multi-resistant to chloramphenicol, ampicillin and cotrimoxazole were isolated in travelers from Asia. Early diagnosis by appropriate bacteriological examination regardless of classical symptomatology should be stressed and the use of fluoroquinolones is warranted in the treatment of typhoid fever.

Adolescent↗

Polymorphism in the interleukin-4 promoter affects acquisition of human immunodeficiency virus type 1 syncytium-inducing phenotype.

The emergence of syncytium-inducing (SI) variants of human immunodeficiency virus type 1 (HIV-1) in infected individuals is an indicator of poor prognosis and is often correlated with faster CD4(+) cell depletion and rapid disease progression. Interleukin-4 (IL-4) is a pleiotropic cytokine with various immune-modulating functions including induction of immunoglobulin E (IgE) production in B cells, down-regulation of CCR5 (a coreceptor for HIV-1 non-SI [NSI] strains), and up-regulation of CXCR4 (a coreceptor for HIV-1 SI variants). Here we show that homozygosity of a polymorphism in the IL-4 promoter region, IL-4 -589T, is correlated with increased rates of SI variant acquisition in HIV-1-infected individuals in Japan. This mutation was also shown to be associated with elevated serum IgE levels in HIV-1-infected individuals, especially in those at advanced stages of disease. In contrast, neither a triallele polymorphism in IL-10, another Th2 cytokine, nor a biallele polymorphism in the RANTES promoter affected acquisition of the SI phenotype. This finding suggested that IL-4-589T increases IL-4 production in the human body and thus accelerates the phenotypic switch of HIV-1 from NSI to SI and possibly disease progression of AIDS.

Alleles↗

[Septicemia].

Explore the source record for details and available documents.

Humans↗

[Causes of death (1983-1997) in patients infected with human immunodeficiency virus by contaminated blood coagulation factor products: report of the clinical study group on prevention and treatments of HIV infection].

Our group conducted a national survey of patients who had died of acquired immunodeficiency syndrome (AIDS) after being infected with human immunodeficiency virus type 1 (HIV-1) by contaminated blood coagulation factor products. A total of 1446 hospitals, clinics, and other health-care institutions throughout Japan were enrolled in the study, which was supported by the Japanese government Ministry of Health and Welfare with a health sciences grant for research on HIV/AIDS. Of the 1434 registered patients who had been infected with HIV-1 by contaminated blood coagulation factor products, 493 (34%) had died as of Oct. 30, 1997. Most were hemophiliacs. The average CD4+ cell count was 25/microliter for the 398 who died of complications from AIDS, compared to an average of 158/microliter for those who died of other causes. Pneumocystis carinii pneumonia, cytomegalovirus infection, and atypical mycobacterial disease were the main causes of death in patients with AIDS. The annual death rate for AIDS patients in Japan dropped dramatically in 1997, 1 year later than a similar trend observed in the United States. The introduction and widespread adoption of new and effective drugs and treatment regimens for HIV-1 and opportunistic infections will be essential life-saving measures.

Acquired Immunodeficiency Syndrome↗

[Varicella in adulthood: clinical features, severity scores, source of infection and complications].

Varicella has been thought to be one of the representative infectious disease in childhood, but recently we are under the impression that adults contracting varicella are increasing in number. On the other hand, they say that varicella generally causes a serious illness in adult patients. So we investigated signs and symptoms of varicella, source of infection, occupations of adult patients, except those who were immunologically compromised, by means of medical records, to know the characteristics of varicella in adulthood. According to the varicella severity score proposed by Nagai et al., varicella in the hospitalized adult patient was found to be much severer than that in children. The most remarkable symptoms, were high fever and sore throat, and these were the main reason of hospitalization in most of our patients. Although severity scores were very high in admitted adult patients with varicella, their clinical courses were not serious, and most of them recovered with only supportive therapy. These patients rarely suffered from complications, like pneumonia. If adult patients with varicella hospitalized in the early stage and received supportive care, they could recover without any complications. In most cases of adult varicella the source of infection was unknown. In the case of married persons, however, many of them were infected through their child. When adults contract varicella, not only the patients themselves suffer from high fever and sore throat, but also they act as the source of infection, if they are medical care workers. Furthermore, in public, the contraction of varicella results a socioeconomic loss from suspension of business caused by the illness. Prophylaxis with varicella vaccine, therefore, should be considered, when there are people who have never contracted varicella, whether or not they are medical staff.

Adult↗