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Biomedical subjects

A Iwamoto

Publications and source records attributed to A Iwamoto.

At least 73 records · Page 4Linked to original sources

Cystic echinococcosis in a Jordanian patient: albendazole in a short-term immigrant.

With an ever increasing number of international travelers, physicians should be aware of the diseases that have rarely been encountered in their home countries. Cystic echinococcosis (CE) caused by Echinococcus granulosus is seldom seen in Japan despite frequent occurrence of the other type of echinococcosis, alveolar echinococcosis (AE) caused by E. multilocularis, in its northern parts. However, CE is prevalent in many parts of the world including the United Kingdom, Mediterranean basin, Middle East, South America, and Australia, and is supposed to be resurgent in several parts of the world. The disease is acquired by the oral ingestion of the eggs of E. granulosus passed into the feces of several definitive host animals carrying tapeworms, mostly dogs. These definitive hosts are infected by cannibalizing intermediate host animals including sheep and cattle whose livers and/or lungs are affected by cystic lesions that contain protoscoleces. In endemic areas the diagnosis of CE is not considered to be complicated; typical morphological features composed of cysts as revealed by ultrasonography and/or computerized tomography (CT) scan. The diagnosis is also aided by serological methods detecting serum antibodies. However, imaging procedures show a variety of features that could often lead to misdiagnosis as other diseases. Moreover, serological assays are sometimes difficult to interpret because of their incomplete sensitivities and specificities. Hence, a comprehensive understanding of a spectrum of imaging features and the application of serological methods with better sensitivities and specificities are indispensable. The mainstay of treatment of the disease is still surgical removal of cysts that has the potential to lead to a complete cure. Recently, the less invasive method PAIR (Puncture of cysts percutaneously, Aspiration of fluid, Introduction of protoscolicidal agent, and Reaspiration) was introduced with considerable success, and could be a promising alternative to surgery. Lastly, medical treatment with oral mebendazole or albendazole, especially the latter, can be beneficial not only as a adjunctive to surgery or PAIR, but as a sole treatment in cases in which invasive methods are not indicated. Here we report a Jordanian patient with CE whose diagnosis was substantiated by a novel immunoblot assay and who showed a rapid improvement during albendazole therapy.

Adult↗

Analysis of receptor usage by ecotropic murine retroviruses, using green fluorescent protein-tagged cationic amino acid transporters.

Entry of ecotropic murine leukemia virus (MuLV) into host cells is initiated by interaction between the receptor-binding domain of the viral SU protein and the third extracellular domain (TED) of the receptor, cationic amino acid transporter 1 (CAT1). To study the molecular basis for the retrovirus-receptor interaction, mouse CAT1 (mCAT1) was expressed in human 293 cells as a fusion protein with jellyfish green fluorescent protein (GFP). Easily detected by fluorescence microscopy and immunoblot analysis with anti-GFP antibodies, the mCAT1-GFP fusion protein was expressed in an N-glycosylated form on the cell surface and in the Golgi apparatus, retaining the ecotropic receptor function. The system was applied to compare Friend MuLV (F-MuLV) and its neuropathogenic variant, PVC-211 MuLV, which exhibits a unique cellular tropism and host range, for the ability to use various CAT family members as a receptor. The results indicated that F-MuLV and PVC-211 MuLV could infect the cells expressing wild-type mCAT1 at comparable efficiencies and that rat CAT3, but not mCAT2, conferred a low but detectable level of susceptibility to F-MuLV and PVC-211 MuLV. The data also suggested that CAT proteins might be expressed in an oligomeric form. Further application of the system developed in this study may provide useful insights into the entry mechanism of ecotropic MuLV.

Amino Acid Sequence↗

Detection of Toxoplasma gondii, Epstein-Barr virus, and JC virus DNAs in the cerebrospinal fluid in acquired immunodeficiency syndrome patients with focal central nervous system complications.

OBJECT: Toxoplasmic encephalitis (TE), primary central nervous system lymphoma (PCNSL) and progressive multifocal leukoencephalopathy (PML) are major central nervous system (CNS) diseases in patients with acquired immunodeficiency syndrome (AIDS). We assessed the diagnostic value of polymerase chain reaction (PCR) in the detection of DNAs of Toxoplasma gondii (T. gondii), Epstein-Barr virus (EBV) and JC virus (JCV) in the cerebrospinal fluid (CSF). METHODS: We compared the PCR results with those of pathological findings at autopsy. PATIENTS OR MATERIALS: The present study included 23 autopsies representing those in whom CSF samples were obtained before death while the patient was hospitalized or at autopsy. RESULTS: The threshold levels for PCR detection were 4 tachyzoites of T. gondii, 5-15 genomes of EBV and 10 genomes of JCV. We identified T. gondii DNA in 4 out of 5 autopsy-defined cases of TE, EBV DNA in 5 out of 5 cases with PCNSL, and JCV DNA in 2 out of 2 cases with PML. The specificity of PCR was 100% in TE, 78% in PCNSL, and 100% in PML. CONCLUSION: Although the number of cases was relatively small in this study, PCR correctly identified T. gondii DNA in those cases in which PML or PCNSL was the sole clinical diagnosis. Our results indicate that PCR examination of CSF is a clinically useful tool for the diagnosis of focal brain lesions in patients with AIDS.

Acquired Immunodeficiency Syndrome↗

[Pyomyositis].

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗

Establishing and characterizing a CD30-positive cell line harboring HHV-8 from a primary effusion lymphoma.

Primary effusion lymphoma (PEL, or body-cavity-based lymphoma [BCBL]) is a new subtype of non-Hodgkin's lymphoma in which tumor cells locate in the body cavity exclusively. PEL/BCBL is widely accepted as one of the neoplastic complications of AIDS, associated mostly with human herpesvirus 8 (HHV-8/Kaposi's sarcoma-associated herpesvirus [KSHV]) and Epstein-Barr virus (EBV). We established and characterized a PEL cell line named TY-1 from a 47-year-old patient with AIDS. TY-1 exhibits indeterminate immunophenotype, expressing CD45 and CD30 cell surface antigens but not expressing B- or T-cell markers. Cytogenetic analysis revealed the representative karyotype of 50,XYq-,+7,+8,+11,+15. Southern blot analysis demonstrated HHV-8 and EBV genomes in the original tumor cells obtained from the pericardial effusion, while HHV-8 but not EBV was detected in TY-1 using PCR or Southern blot analysis. Tetradecanylphorbol acetate treatment induced some TY-1 cells to proceed to the reproductive phase. This cell line may be an useful tool for research on PEL and HHV-8.

Fatal Outcome↗

Pulmonary nodule mimicking lung cancer in a human immunodeficiency virus type-1 infected patient.

We reported a human immunodeficiency virus type 1-infected patient with a small solitary pulmonary nodule mimicking adenocarcinoma, who was treated successfully with antituberculosis therapy. We believe that high-resolution CT scans of thorax are important examinations to detect pulmonary inflammatory findings, such as ectasis of the bronchi leading to the nodules and calcifications in the nodules, and also as follow-up tests for evaluating effectiveness of treatment on pulmonary inflammatory nodules in human immunodeficiency virus type 1-infected patients.

Acquired Immunodeficiency Syndrome↗

Anti-HIV-1 and chemotactic activities of human stromal cell-derived factor 1alpha (SDF-1alpha) and SDF-1beta are abolished by CD26/dipeptidyl peptidase IV-mediated cleavage.

CD26 is a leukocyte-activation antigen that is expressed on T lymphocytes and macrophages and possesses dipeptidyl peptidase IV (DPPIV) activity, whose natural substrates have not been identified yet. CXC chemokines, stromal cell-derived factor 1alpha (SDF-1alpha) and 1beta (SDF-1beta), sharing the receptor CXCR-4, are highly efficacious chemoattractants for resting lymphocytes and CD34(+) progenitor cells, and they efficiently block the CXCR-4-mediated entry into cells of T cell line tropic strains of HIV type 1 (HIV-1). Here we show that both the chemotactic and antiviral activities of these chemokines are abrogated by DPPIV-mediated specific removal of the N-terminal dipeptide, not only when the chemokines are produced in transformed mouse L cell line to express human CD26 but also when they were exposed to a human T cell line (H9) physiologically expressing CD26. Mutagenesis of SDF-1alpha confirmed the critical requirement of the N-terminal dipeptide for its chemotactic and antiviral activities. These data suggest that CD26-mediated cleavage of SDF-1alpha and SDF-1beta likely occurs in human bodies and promotes HIV-1 replication and disease progression. They may also explain why memory function of CD4(+) cells is preferentially lost in HIV-1 infection. Furthermore, CD26 would modulate various other biological processes in which SDF-1alpha and SDF-1beta are involved.

Animals↗

High SDF-1 expression in HIV-1 carriers does not correlate with CD8+ T-cell-mediated suppression of viral replication.

Stromal cell-derived factor 1 (SDF-1) inhibits T-cell tropic (T-tropic) HIV-1 infection in vitro. In this study, we examined the regulatory role of SDF-1 on HIV-1 replication in peripheral blood mononuclear cells (PBMC) of HIV-infected individuals. We found that the amount of SDF-1 mRNA in freshly isolated PBMC of HIV-1 carriers was higher than in healthy donors. Moreover, PBMC from some asymptomatic carriers (ACs) exhibited high levels of SDF-1 mRNA expression. The level of SDF-1 expression in PBMC did not correlate with the magnitude of CD8+ T-cell-mediated suppression of HIV-1 among ACs SDF-1 inhibited HIV-1 replication at the viral entry step, whereas a single-cycle HIV-1 infection system showed that the major part of the CD8+ T-cell-mediated suppression occurs after intracellular penetration of the virus. Our results suggest that SDF-1 acts as a suppressor of virus replication in a CD8+ T-cell-independent mechanism in HIV-infected individuals.

Base Sequence↗

Type V phosphodiesterase inhibition modulates endogenous immunoreactivities of endothelin-1 and endothelial nitric oxide synthase in pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension.

We evaluated the effects of oral administration of E4021 (100 mg/kg/day), a type V phosphodiesterase inhibitor, on immunoreactivities of endothelin-1, endothelin receptors, and nitric oxide synthases in pulmonary arteries in a rat model of pulmonary hypertension. Immunoreactivities of endothelin-1 and endothelial nitric oxide synthase were observed significantly less frequently, together with significant reduction of right ventricular overload and medial thickening in rats treated with E4021 than in the control with monocrotaline on day 28. The levels of plasma endothelin-1 and serum nitrite and nitrate were significantly lower in rats that received E4021 than in the control with monocrotaline. Oral administration of E4021 modulates endogenous immunoreactivities of endothelin-1 and endothelial nitric oxide synthase with the improvement or right ventricular overload and medial thickening.

3',5'-Cyclic-GMP Phosphodiesterases↗