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I Nagano

Publications and source records attributed to I Nagano.

At least 109 records · Page 6Linked to original sources
PubMed1995

DNA single-strand breaks in postischemic gerbil brain detected by in situ nick translation procedure.

Using an in situ nick translation procedure, DNA single-strand breaks (SSB) in postischemic gerbil hippocampus were investigated after 15-min forebrain ischemia followed by 0-4h of recirculation. In the control group, increased SSB were noticed in the ependymal cell layer and the dentate gyrus. After 15-min ischemia without recirculation, no remarkable changes in SSB were observed. However, after 1 h of recirculation, a marked increase in SSB was recognized throughout the hippocampus, especially in the cells in CA1 subfield and the dentate gyrus. After 4 h of recirculation, SSB decreased to a level near that of the control group. The results of the present study indicate that ischemic insults may injure intranuclear DNA during postischemic recirculation periods. Although many factors may be involved, activated endonuclease due to an intracellular Ca2+ rise, free radicals, and postischemic hyperthermia appear to be involved in this phenomenon.

Animals↗
PubMed1995

HIV-1 heterogeneity and cytokines. Neuropathogenesis.

Mild manifestations (HIV-1 associated minor cognitive/motor disorder), severe manifestations (HIV-1 associated dementia complex and HIV-1 associated myelopathy), and sensory neuropathy are consequences of HIV-1 infection. Our goal is to elucidate the role of HIV-1 in the complications of AIDS including cytokine immunopathology and HIV-1 DNA sequence variants. We have examined the brain and sensory ganglia from 60 AIDS patients and 20 seronegative controls using PCR, DNA sequencing of the HIV-1 envelope protein (env), in situ hybridization (ISH), and immunohistochemistry (IHC). Using our combined ISH-IHC technique, we could identify different types of cells and HIV-1 simultaneously in cryostat and paraffin sections. We found HIV-1 predominantly in macrophage/microglia in brain. In dorsal root ganglia (DRG) we found rare macrophages infected with HIV-1 and neurons and interstitial cells (including macrophages) which were apoptotic. Cytokines were detected in mononuclear and endothelial cells near neurons. We achieved single copy sensitivity detecting HIV-1 in nervous tissue using nested PCR. We sequenced HIV-1, DNA from 3 intravenous drug users (IDUs): from brain, CSF, and blood. PCR amplification was followed by cloning and then sequencing the HIV-1 insert: V1-V5 regions of the envelope (env) gene. We found that the env genes had increased sequence variation compared to the literature, cDNA sequences derived from RNA were less heterogeneous than clones derived from DNA from the same specimens, clones derived from brain are more closely related (show restricted heterogeneity) compared to clones from blood and CSF from the same patients. Patient 149 clones we examined to date did not correspond to any of the designated subtypes (A-F) of HIV-1 based on the DNA sequences of the C2-V3 regions. Finally, the HIV-1 RNA produced in these tissues is derived from a minority of DNA clones. Although HIV-1 infected macrophages are not entirely responsible for pathology in the brain and less so in sensory ganglia, some of the products of infection, cytokines, are more widespread in these tissues. Furthermore, HIV-1 strains infecting the brain appear to exhibit restricted heterogeneity compared to autologous CSF and blood and these strains may be associated with cytokines and pathology. HIV-1 strains that infect nervous tissue and cytokines produced in this tissue may effect neuropathogenesis, in vivo, in spite of low levels of local HIV-1 infection. We attempt to delineate, here, common sequence variations in HIV-1 isolates in the hope of developing future therapeutic strategies.

AIDS Dementia Complex↗
PubMed1995

Role of immune activation and cytokine expression in HIV-1-associated neurologic diseases.

Central nervous system (CNS) involvement is common during human immunodeficiency virus type-1 (HIV-1) infection. The neurologic disease of the CNS most frequently observed during acquired immunodeficiency syndrome (AIDS) is HIV-1-associated cognitive/motor complex or AIDS dementia complex (ADC), which is most likely a direct consequence of HIV-1 infection of the CNS. The peripheral nervous system (PNS) is also affected in HIV-1-infected individuals and there are several features of immune- and cytokine-related pathogenesis in both the CNS and PNS that are reviewed. Several lines of evidence demonstrate aspects of immune activation in the CNS and peripheral nervous system (PNS) of HIV-1-infected individuals. The relative paucity of HIV-1 expression in contrast to widespread functional and pathologic changes in the CNS and PNS of AIDS patients, and the lack of evidence of productive infection of HIV-1 in neuronal cells in vivo lead to the possibility of indirect or immunopathogenic mechanisms for HIV-1-related neurologic diseases. Proposed mechanisms of neuronal and glial cell damage are injury of oligodendrocytes by tumor necrosis factor-alpha (TNF-alpha) released from activated macrophage/microglia, calcium-dependent excitoneurotoxicity induced by gp120 HIV-1 envelope protein, N-methyl-D-aspartate (NMDA) receptor-mediated neurotoxicity by quinolinic acid (a product of activated macrophages), cell injury by HIV-1-specific cytotoxic T cells, and apoptosis of oligodendrocytes or neurons triggered by interaction between cell surface receptors and HIV-1 gp120 protein. Common to those mechanisms is the dependence on cellular activation with expression of proinflammatory cytokines (TNF-alpha, interleukin-1). Amplification of activation signals through the cytokine network by macrophage/astrocyte/endothelial cell interactions, and cell-to-cell contact between activated macrophages and neural cells by upregulation of adhesion molecules dramatically enhances the toxic effect of macrophage products. Expression of immunosuppressive cytokines such as interleukin-4, interleukin-6, and transforming growth factor-beta is also increased in the CNS and PNS of HIV-1-infected patients. This may serve as neuroprotective and regenerative mechanism against insults to nervous system tissue.

AIDS Dementia Complex↗
PubMed1995

Immunocytochemical detection of tumor necrosis factor-alpha in infiltrating tumor cells in the cerebrospinal fluid from five patients with leptomeningeal carcinomatosis.

We studied the immunoreactivity for tumor necrosis factor-alpha (TNF-alpha) in cerebrospinal fluid (CSF) cell smears from five patients with leptomeningeal carcinomatosis (LC). Immunostained TNF-alpha-positive tumor cells had brownish deposits in the cytoplasm, but no deposits were observed in the nucleus. The intensity of the TNF-alpha staining was greater in these tumor cells than in macrophages from patients with inflammatory diseases. Approximately 27-72% of the tumor cells were found to be TNF-alpha immunoreactive in all five samples from the patient with LC. These results suggest that the large amount of TNF-alpha produced by infiltrating tumor cells may play an important role in the development of the tumor.

Adenocarcinoma↗
PubMed1994

Transmission of Rickettsia tsutsugamushi strains among humans, wild rodents, and trombiculid mites in an area of Japan in which tsutsugamushi disease is newly endemic.

Thirty-two newly isolated strains of Rickettsia tsutsugamushi, 14 from patients with tsutsugamushi disease, 12 from wild rodents, and 6 from trombiculid mites parasitizing rodents in Gifu Prefecture, Japan, were examined for reactivities to 12 monoclonal antibodies by an indirect fluorescent-antibody test to classify their antigenicities. All of the isolates could be classified into one of six groups (KN-1, KN-2, KN-3, GJ-1, R158, and R161) according to their reactivities to the monoclonal antibodies. The KN-1 and GJ-1 strains that are prevalent among patients from Gifu Prefecture had the same reactivities as the Kawasaki and Kuroki strains, respectively, which have been isolated and are prevalent in the Miyazaki and Kagoshima prefectures in southwest Japan. The isolates from patients were different in serotype from those from rodents and mites (Leptotrombidium pallidum). The KN-2 and KN-3 strains were most prevalent among patients and among rodents and mites, respectively. No close similarity between KN-2 and other strains tested was observed. KN-3 is only a minor contributor to diseases in patients in Gifu Prefecture; however, it was proven that the same strain was prevalent in Niigata Prefecture in northern Japan. Thus, Gifu Prefecture is an area where southern, northern, and local strains are found. We hypothesize that humans are prone to infection with KN-2, GJ-1 (very similar to Kuroki), and KN-1 (very similar to Kawasaki), probably by infestation with Leptotrombidium scutellare. While both L. scutellare and L. pallidum parasitize wild rodents and may carry any rickettsial strain, the most virulent strain, KN-3, is predominant among wild rodents. Antigenic analysis using monoclonal antibodies to R. tsutsugamushi should be useful for epidemiological studies of infection with this organism.

Animals↗
PubMed1994

Expression of cytokines in brain lesions in subacute sclerosing panencephalitis.

We analyzed frozen brain specimens from three patients with subacute sclerosing panencephalitis (SSPE) for the presence of interleukin (IL)-1 beta, IL-2, IL-6, tumor necrosis factor (TNF), lymphotoxin (LT), and interferon (IFN)-gamma using immunocytochemical techniques. We detected these cytokines in SSPE brain lesions demonstrating extensive cellular infiltrates, demyelination, and gliosis. Double-label immunocytochemistry, using cell-specific markers, showed that positive immunoreactivity for these cytokines was present on both infiltrating cells and resident brain cells. We also found IL-6, TNF, and IFN-gamma at lower levels in brain tissue from a patient with progressive multifocal leukoencephalopathy. In contrast, normal control brain sections showed no reactivity for any of the cytokines. These findings indicate that IL-1 beta, IL-2, IL-6, TNT, LT, and IFN-gamma may be produced in SSPE lesions and may be involved in the lesion pathogenesis of SSPE.

Adult↗
PubMed1994

Hepatic mitochondrial changes in experimental obstructive jaundice complicated by biliary infection.

The effects of biliary infection on the structural and functional changes in the liver in obstructive jaundice was studied using rats as experimental animals. Biliary infection with obstructive jaundice was induced in the animals by injecting Escherichia coli into the common bile duct through a nylon tube cannulated into the duct. This was followed by the clamping of the tube. For the controls, the tube was clamped in the absence of Escherichia coli. After 3, 7, 14 and 21 days, the animals were sacrificed, and some serum enzyme activities, histological changes in the liver, and the coupling efficiency of mitochondria isolated from the liver were investigated. The phosphorylating ability of hepatic mitochondria was more seriously affected when the obstruction was complicated by cholangitis. We suggest that, when associated with obstructive jaundice, biliary infection should be carefully treated prior to hepatectomy.

Alanine Transaminase↗
PubMed1994

Hepatic recovery after biliary drainage in experimental obstructive jaundice complicated by biliary infection.

The effects of an association of biliary infection and bile stasis on the recovery process of the impaired structure and function of the cholestatic liver after biliary drainage were studied in experimental animals. Obstructive jaundice was induced by clamping a tube inserted into the common bile duct of rats, while at the same time Escherichia coli bacteria were introduced into the tube to induce biliary infection. After one week, the biliary obstruction was removed. After 14 days of biliary drainage, the impaired structure and function of the cholestatic liver without biliary infection were remarkably improved, having returned almost to normal, while in the cases with biliary infection, the impairments were far less improved, especially with respect to mitochondrial function. These results suggest that major hepatic surgery should not be employed in patients with obstructive jaundice in the presence of biliary infection and should be delayed until hepatic function has recovered sufficiently after biliary drainage.

Animals↗
PubMed1993

Detection of tumor necrosis factor-alpha-positive cells in cerebrospinal fluid of patients with HTLV-I-associated myelopathy.

Tumor necrosis factor (TNF)-alpha-positive cells constituted 1.6-18% and 8.2-23.5% of the total number of cerebrospinal fluid cells from six of 12 patients with HTLV-I-associated myelopathy and in all samples obtained from inflammatory cases, respectively. However, in non-inflammatory cases no TNF-alpha-positive cells were detected. These results suggest that some of the infiltrating CSF cells produce TNF-alpha, which plays a role in host immune defenses against causative agents including HTLV-I and in lesion formation within the central nervous system in inflammatory diseases.

Adult↗
PubMed1992

Distributions of heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 mRNAs after transient focal ischemia in rat brain.

The distribution of heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 mRNA after 30 min of middle cerebral artery (MCA) occlusion was investigated in rat brain by in situ hybridization using cloned cDNA probes selective for the mRNAs. While HSP70 mRNA was hardly present at caudate and dorsal hippocampal levels of the sham brain this mRNA was greatly induced in cells of the MCA territory 1 h after reperfusion. Although the maximum amount of induced HSP70 mRNA in the caudate was much smaller than that in the cortex the maximum induction in the caudate (3 h) preceded that in the cortex (8 h). In contrast to the case of HSP70 mRNA, HSC70 mRNA was present in most cells of the sham brain, and was especially dense in hippocampal CA3 cells. Further induction of HSC70 mRNA was observed after reperfusion in the same cell populations, as in the case of HSP70 mRNA. HSC70 mRNA levels were significantly reduced in the caudate at 8 h when small amounts of HSP70 mRNA were still elevated. In the ipsilateral granule cells of the dentate gyrus and hippocampal CA3 cells a slight but significant induction of HSC70 mRNA was observed from 1 h to 1 day, while obvious induction of HSP70 mRNA never occurred. All the induced signals of HSP70 and HSC70 mRNA were diminished or returned to the sham level by 7 days, except for HSC70 mRNA in the caudate. These results are the first observations of the distribution of HSP70 and HSC70 mRNA after transient focal ischemia of rat brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Distributions of heat shock protein-70 mRNAs and heat shock cognate protein-70 mRNAs after transient global ischemia in gerbil brain.

Distributions of heat shock protein (HSP)-70 mRNAs and heat shock cognate protein (HSC)-70 mRNAs after 10 min of transient global ischemia were investigated in gerbil forebrain by in situ hybridization using cloned cDNA probes selective for the mRNAs. Expression of HSP70 immunoreactivity was also examined in the same brains. In hippocampal CA1 neuronal cells, in which only a minimal induction of immunoreactive HSP70 protein was found, the strong hybridization for HSP70 mRNA disappeared at around 2 days before the death of CA1 cells became evident. Furthermore, in hippocampal CA3 cells, a striking induction of HSP70 mRNA was sustained even at 2 days along with a prominent accumulation of HSP70 immunoreactivity. In contrast to the case of HSP70 mRNA, HSC70 mRNA was present in most neuronal cells, especially dense in CA3 cells, of the sham brain. A co-induction of HSP70 and HSC70 mRNAs was observed in several cell populations after the reperfusion with a peak at 8 h, although the magnitude of HSC70 mRNA induction was lower than that of HSP70 mRNA, particularly in CA1 cells. The expression of HSC70 mRNA in CA1 cells also disappeared at around 2 days. All the induced signals of HSP70 and HSC70 mRNAs in other cell populations were diminished and returned to the sham level, respectively, by 7 days. These results are the first to show the time courses of distribution of HSP70 and HSC70 mRNAs and the immunoreactive HSP70 protein in the same gerbil brain after ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Studies on tsutsugamushi diseases in Gifu Prefecture. 5. Characterization of monoclonal antibodies to prototype strains of Rickettsia tsutsugamushi and immunological grouping of newly isolated strains using the antibodies].

We characterized 8 monoclonal antibodies (MAbs) to Karp, Kato, and Gilliam strains of Rickettsia tsutsugamushi, and analysed 17 isolates from patients with Tsutsugamushi disease using these MAbs. These were divided into 3 strain-specific (Kp/D11, Kt/2D9, and Gi/E4) and 5 cross-reactive MAbs (Kp/1F11, Kp/1C10, Kp/C6, Kt/3B2, and Kt/3C2). All MAbs recognized characteristic protein antigens using the indirect fluorescent-antibody test (IFA) and proteinase K treatment. Analysis by polyacrylamide gel electrophoresis and immunoblotting techniques revealed that Kato-specific MAb Kt/2D9 recognized a polypeptide with a molecular mass of 54 kilodalton (kDa) of the homologous strain, and cross-reactive MAbs Kp/1F11, Kp/C6, and Kt/3B2 recognized those of 46-47 kDa, 46-47 KDa, and 60 kDa, respectively to the homologous and heterologous strains. MAbs Kp/1C10 which exhibited a high IFA titer against the Karp strain and only low titers against heterologous strains recognized only the 110 kDa polypeptide of the homologous strain. MAb Kt/3C2 which reacted with both Karp and Kato strains recognized a 54 to 56 kDa polypeptide band of the two prototype strains as well as several other polypeptides, however, each molecular mass was present in only one of two strains. Testing by the plaque reduction technique showed another characteristic of MAb Kt/3C2 to neutralize both Karp and Kato Strains. Fourteen isolated strains from patients in the south and west regions of Gifu Prefecture, the Shimokoshi stain isolated in Niigata Prefecture, and Kawasaki and Kuroki stains isolated in Miyazaki Prefecture were examined for reactivities to 8 MAbs by IFA to classify their antigenicities. No isolated strains reacted with Karp-specific Kp/D11, Kato-specific Kt/2D9, or Gilliam-specific Gi/E4.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Detection of interferon-gamma and IL-6 producing cells in cerebrospinal fluid cells in the central nervous system infectious diseases using immunocytochemistry].

To evaluate the relationship between cytokines and cerebrospinal fluid (CSF) cells, we detected interferon (IFN)-gamma and interleukin (IL)-6 producing cells in CSF from the patients with central nervous system (CNS) infectious diseases by immunocytochemistry. Five CSF cell smears from three herpes encephalitis patients, three from a patient with EB virus radiculoneuritis, four from the three patients with purulent meningitis, five from five patients with viral meningitis were obtained during early or subacute stages of diseases. Control CSF cell smears were taken from twenty seven patients with motor neuron disease, Parkinson's disease and spinocerebellar degeneration. Immunocytochemistry using specific polyclonal anti-IFN-gamma and IL-6 sera were used to detect each producing cell. Simultaneously, individual positively immuno-reactive cells were morphologically classified macrophage or lymphocyte. The IFN-gamma positive cells immunostained with specific antibody showed brown-colored deposits within the cytoplasm whereas no deposit was in the nucleus (Fig. 1). These phenotype of IFN-gamma positive cells were considered to be lymphocytes or macrophages. However, IFN-gamma-positive macrophages were predominantly seen at the early stages of herpes simplex encephalitis and purulent meningitis. The percent of IFN-gamma positive cells in total CSF cells obtained from the patients with the CNS infectious diseases was 2.3-38.7 as shown in Table 1. The IL-6 positive cells (Fig. 2) were also found early in the course and in subacute stages in the CNS infectious diseases and ranged from 2.5-50 percent in total CSF cells (Table 1). In contrast neither IFN-gamma- nor IL-6-positive cells were detected in non-inflammatory diseases (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Central Nervous System Diseases↗
PubMed1991

[Fundamental study on serological diagnosis of amoebiasis. 3. Serological survey of amoebiasis in blood donors showing seropositive for syphilis].

Sera of 375 blood donors which were seropositive for syphilis were examined for antibodies against Entamoeba histolytica. Antibody prevalences against E. histolytica using complement fixation (CF) test were 12.0%, and enzyme-linked immunosorbent assay (ELISA) were 2.7%. The positive rates of antibodies in the CF test were significantly higher in sera showing positive by the Venereal Disease Research Laboratory (VDRL) test than in the VDRL-negative sera, and not related to the results of Treponema pallidum hemagglutination (TPHA) test. Only one sample in the VDRL-negative sera was positive by CF test. On the other hand, the positive rates or mean absorbance in ELISA were not correlated to the results of VDRL or TPHA test. The percent positivity in CF test became higher with the level of antibodies in VDRL test, but not that in ELISA. The level of antibodies in CF and VDRL test were weakly correlated. These results suggested that the results of CF test for E. histolytica antibodies were most likely false-positive in relation to the results of VDRL test. 10 (2.7%) of sera were positive by ELISA, but all ELISA-positive samples showed low ELISA titers and absorbance. 9 of the ELISA-positive samples showed indirect fluorescent antibody (IFA) titers of over 1:50, and the level of antibodies in the IFA test correlated to that in ELISA, so ELISA-positive persons seemed to have been previous infected or were asymptomatic cyst carriers.

Adolescent↗
PubMed1991

[Studies on tsutsugamushi disease in Gifu prefecture. 4. Survey results in Ena and Takayama City, and the summary of the studies in the prefecture].

Investigations of trombiculid mites and Rickettsia tsutsugamushi in wild rodents were made in Ena (Nov. 1988) and Takayama (May 1989) City. In the former area where no patient has been reported so far, Leptotrombidium pallidum (63.9%) was most predominant and no L. scutellare was found. A Karp-related rickettsia (11.1%) was isolated from wild rodents and 30% of them had antibody to R. tsutsugamushi (anti-Karp was prominent). The latter area where patients were reported in spring as well as in autumn, L. pallidum (22.4%) was one of the dominant species in spring. Karp-related strains were isolated from 37.5% of wild rodents. And the antibody possession rate was 50.0%. These data reconfirmed our hypothesis that the majority of patients in autumn were infected by L. scutellare and a part by L. pallidum. In spring in Takayama area, the vector was L. pallidum which possessed Karp-related strain(s).

Animals↗
PubMed1991

Immunocytochemical analysis of the cellular infiltrate in brain lesions in subacute sclerosing panencephalitis.

We studied lymphocyte subsets and major histocompatibility complex (MHC) class II antigens in frozen brain tissues from three patients with subacute sclerosing panencephalitis (SSPE) using immunocytochemical techniques. Perivascular cuffs consisted predominantly of T cells and MHC class II-positive cells. In the parenchymal lesions, there were frequent B and CD4+ cells. MHC class II-positive cells were also diffusely distributed throughout the parenchyma. There were more CD4+ than CD8+ cells both in the parenchyma and in the perivascular cuffs. These findings suggest an overrepresentation of CD4+ cells in SSPE lesions and that CD4+ cells may be involved in the pathogenesis of SSPE.

Adult↗
PubMed1990

[Fundamental studies on serological diagnosis of amoebiasis. 2. Application of antigen of Entamoeba histolytica for complement fixation test to counterimmunoelectrophoresis; and clinical relevance of serological tests].

Antigen of Entamoeba histolytica for complement fixation (CF) test was applied to counterimmunoelectrophoresis (CIE), and the result was compared with that of CF test and enzyme-linked immunosorbent assay (ELISA) in regard to sensitivity and specificity. Besides, we studied antibody titers to E. histolytica in sera from acute and convalescent patients, and from patients with amoebic colitis and amoebic liver abscess. Sera used were from patients with amoebic colitis, amoebic liver abscess and uninfected control subjects. The CIE was less sensitive than the CF test and ELISA. Most CIE-negative samples had low CF and ELISA titers, but a few samples had higher CF and ELISA titers. On the other hand, all uninfected controls were negative by CIE and ELISA, and 98% were negative by the CF test. The level of antibodies tended to decrease with time after clinical recovery, but CF test and ELISA results remained positive in all patients 6 months after clinical cure. CIE converted negative in only one patient after 6 months. The level of antibodies of CF test and ELISA was significantly higher in amoebic liver abscess than amoebic colitis. These results suggested that all these three methods were so specific, and antibody titers by the CF test and ELISA were well correlated to clinical manifestations. The CIE with CF-antigen was less sensitive as compared with CF test or ELISA.

Animals↗