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Biomedical subjects

Manabu Ikeda

Publications and source records attributed to Manabu Ikeda.

At least 19 recordsLinked to original sources
PubMed2005

Imbalance of tumor necrosis factor receptors during progression in bovine leukemia virus infection.

Previously, we found an up-regulation of tumor necrosis factor alpha (TNF)-alpha and an imbalance of TNF receptors in sheep experimentally infected with bovine leukemia virus (BLV). In order to investigate the different TNF-alpha-induced responses, in this study we examined the TNF-alpha-induced proliferative response and the expression levels of two distinct TNF receptors on peripheral blood mononuclear cells (PBMC) derived from BLV-uninfected cattle and BLV-infected cattle that were aleukemic (AL) or had persistent lymphocytosis (PL). The proliferative response of PBMC isolated from those cattle with PL in the presence of recombinant bovine TNF-alpha (rTNF-alpha) was significantly higher than those from AL cattle and uninfected cattle and the cells from PL cattle expressed significantly higher mRNA levels of TNF receptor type II (TNF-RII) than those from AL and BLV-uninfected cattle. No difference was found in TNF-RI mRNA levels. Most cells expressing TNF-RII in PL cattle were CD5+ or sIgM+ cells and these cells showed resistance to TNF-alpha-induced apoptosis. Additionally, there were significant positive correlations between the changes in provirus load and TNF-RII mRNA levels, and TNF-alpha-induced proliferation and TNF-RII mRNA levels. These data suggest that imbalance in the expression of TNF receptors could at least in part contribute to the progression of lymphocytosis in BLV infection.

Animals↗
PubMed2005

Abnormal development of nephrons in claudin-16-defective Japanese black cattle.

The kidneys of 37 Japanese Black calves aged 2 to 65 months diagnosed with Claudin 16 (CL-16) defect by the DNA-based test were examined pathologically. The animals exhibited clinical symptoms such as growth impairment, renal failure, overgrowth of hooves, and anemia at a young age. There was no correlation between the time of onset and age. Kidney weights relative to body weight were similar to those in normal animals, but both kidney net weights and size were reduced due to atrophy in animals that showed severe renal dysfunction. Histopathological examination of the kidneys showed reduction in the number of glomeruli, compensatory hypertrophy of glomeruli and tubules, and glomerular and tubular atrophy accompanied by interstitial fibrosis and lymphocytic infiltration. Glomeruli were clearly less in number in the kidneys of CL-16-defective animals than those of normal animals even in the cases with mild lesions. A small number of immature glomeruli and tubules were also detected, suggesting that there were fewer nephrons developed at birth in CL-16-defective animals. It was suggested that a defect of the CL-16 gene is involved in the "abnormal development of nephrons". Immunohistopathological examination of the kidneys showed that the epithelium of thick ascending limb of Henle was stained with anti-CL-16 antibody in the control animals, but not in the affected animals, suggesting a defect of CL-16 in the epithelium of renal tubules in the affected animals.

Abnormalities, Multiple↗
PubMed2005

Immunohistochemical analysis of expression patterns of tumor necrosis factor receptors on lymphoma cells in enzootic bovine leukosis.

Tumor necrosis factor-alpha (TNF-alpha) has been reported to be associated with the progression of lymphoproliferative neoplastic diseases and retroviral infections. Hence we examined immunohistochemically the expression patterns of TNF-receptors (TNF-RI and RII) on lymphoma cells derived from the 29 cases of enzootic bovine leukosis (EBL). Lymphomas obtained in 29 animals with EBL were histopathologically classified into three types: diffuse mixed type (10 cases), diffuse large type (9 cases), and diffuse large cleaved type (10 cases). Immunohistochemically using a monoclonal antibody to a bovine lymphocyte surface antigen, the lymphomas were classified into three phenotypes: B-1a (CD5+/CD11b+), B-1b (CD5-/CD11b+) and B-2 (conventional B) (CD5-/CD11b-). Interestingly, the lymphoma cells in all animals expressed TNF-RII, but not TNF-RI. Although, in EBL, lymphoma cells of which the histopathological and immunological property differs has been formed, the expression patterns of TNF-Rs had the universality in all lymphoma cells. TNF-RII, which induces cell proliferation, was expressed but TNF-RI, which induces cell apoptosis was not expressed on all lymphoma cells, suggesting that TNF-Rs play an important role in the malignant proliferation of B cells and formation of lymphomas in EBL.

Animals↗
PubMed2005

[Dementia and driving: present status of drivers with dementia and response of their family's care in Japan].

As a result of the growing proportion of drivers aged 65 years and older, it is estimated that the number of elderly drivers with dementia is increasing in Japan. Since June 2002, if a driver is found to be "demented", his/her driving license shall be revoked in Japan. However, there are no consensus guidelines for demented drivers. Between September 1995 and September 2001, we evaluated 30 drivers with dementia (19 males and 11 females, mean age of 69.4 years) in out patients clinic of the Kochi Medical School Hospital and related hospitals. Clinical Diagnosis was Alzheimer's disease in 20, vascular dementia in 3, mixed type dementia in 2, frontotemporal lobar degeneration in 4, other type dementia in 1. We analyzed their driving behavior and family's attitude. Seventy-three point three percent of 30 drivers with dementia continued to drive after diagnosis. In follow-up periods, number of drivers continuing driving was decreased to 13 (43.3%), while six drivers (27.3%) had a traffic accident or violation. Our study suggests that several important medical and social factors should be considered for the management of drivers with dementia. A consensus medical guideline for demented drivers has to be established.

Accidents, Traffic↗
PubMed2004

Efficacy of fluvoxamine as a treatment for behavioral symptoms in frontotemporal lobar degeneration patients.

Patients with frontotemporal lobar degeneration (FTLD) present a profound personality change, social misconduct, overeating, and stereotyped behavior. We examined the hypothesis that many of the behavioral symptoms of FTLD will respond to selective serotonin reuptake inhibitors (SSRIs). Sixteen FTLD patients were treated with an SSRI (fluvoxamine maleate) in an open 12-week trial. Treatment responses for stereotyped behavior and other neurobehavioral symptoms were evaluated by the Stereotypy Rating Inventory and the Neuropsychiatric Inventory. The behavioral symptoms, especially stereotyped behaviors of FTLD, significantly improved after treatment. Randomized, placebo- and other SSRI-controlled trials may improve available treatments.

Aged↗
PubMed2004

Heterogeneity of cerebral blood flow in frontotemporal lobar degeneration and Alzheimer's disease.

This study was designed to quantify the heterogeneity on cerebral blood flow single-photon emission tomography (SPET) images in frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) using a three-dimensional fractal analysis. Twenty-one FTLD patients, 21 AD patients and 11 healthy controls underwent technetium-99m hexamethylpropylene amine oxime SPET scanning. Patients with FTLD and AD matched for sex, age and the severity of dementia as estimated with the Clinical Dementia Rating and were determined to be in the early stage of illness. We delineated the SPET images using a 35% cut-off and a 50% cut-off of the maximal voxel radioactivity and measured the number of voxels included in the contours of two different cut-offs. The fractal dimension (FD) was calculated by relating the logarithms of the cut-offs and the numbers of voxels, and it was defined as the heterogeneity of the cerebral perfusion. We divided the SPET images into two sets, anterior and posterior, with equal numbers of coronal SPET slices. We calculated total FD, anterior FD and posterior FD for total, anterior and posterior SPET images. Anterior FDs for FTLD and AD were 1.55 +/- 0.34 and 1.24 +/- 0.19 (P = 0.0002). The ratios of anterior to posterior FD for FTLD and AD were 1.81 +/- 0.41 and 1.32 +/- 0.14 (P < 0.0001). Use of the anterior FD and the ratio of anterior to posterior FD separated FTLD patients from AD patients and controls with a sensitivity of 85.7% and a specificity of 93.8%. Anterior FD and the ratio of anterior to posterior FD may be useful in distinguishing FTLD from AD.

Aged↗
PubMed2004

Epidemiology of frontotemporal lobar degeneration.

A few epidemiologic studies have dealt with the prevalence of frontotemporal lobar degeneration (FTLD), including Pick's disease. The aim of this study was to review the epidemiologic studies of FTLD in western countries and to compare them with those in Japan. A community-based study of early-onset dementia in London revealed that 12% of cases with frontotemporal dementia (FTD) fulfilled the Lund-Manchester criteria in contrast to 34% of cases with Alzheimer's disease (AD) in a sample of 185 cases. The Cambridge Group has recently examined the prevalence of early-onset dementia in a community-based study. Of 108 cases, 15.7% had FTLD and 25% had AD. FTLD included 13 FTD cases, and 2 each with semantic dementia (SD) and nonfluent progressive aphasia (PA). Almost one third of cases with FTLD (29%) had a positive family history. Of our consecutive 330 outpatients with dementia (hospital setting without age limitation), 42 (12.7%) had FTLD and 215 (65.1%) had AD. In our series of patients, 22 FTD, 15 SD and 5 PA cases were identified. There was no family history in all subtypes of FTLD. Epidemiologic studies, both community-based and hospital-based, demonstrate that FTLD is a more common cause of early-onset dementia than previously recognized. Regarding the subtypes of FTLD, in Japan, compared with the data from the UK, FTD is less common, SD may be more common and PA is equally common. The reason for this discrepancy is supposed to be mainly based on the role of heredity.

Age Distribution↗
PubMed2004

[Pick complex].

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Basal Ganglia↗
PubMed2003

Delusions of Japanese patients with Alzheimer's disease.

BACKGROUND: Delusions constitute one of the most prominent psychiatric complications in Alzheimer's disease (AD). However, there is little consensus of the prevalence and associated factors for delusions in AD. AIMS: To reveal the characteristics of delusions among Japanese patients with AD. METHOD: 112 consecutive patients with AD were recruited over a one year period and administered the Neuropsychiatric Inventory (NPI). RESULTS: Delusions were present in 53 patients (47.3%). Delusions of theft were the most common type of delusion (75.5% of patients with delusions), followed by misidentification delusions and delusions of suspicion. More hallucination, agitation, and female gender were found in the delusions group. CONCLUSIONS: The authors found a high frequency of delusions, particularly of delusions of theft and suggested that gender was associated with the expression of delusions in Japanese patients with AD.

Aged↗
PubMed2003

Surface dyslexia in a Japanese patient with semantic dementia: evidence for similarity-based orthography-to-phonology translation.

We studied the reading performance of a Japanese-speaking patient, TI, with bilateral but asymmetrical (left more than right) temporal-lobe atrophy, severe anomia, and poor word comprehension. Most Japanese kanji characters correspond to several different legitimate pronunciations in different contexts, with varying degrees of correspondence consistency. TI made many errors in reading aloud words that violate statistically typical character-sound correspondences, especially for less common words, but had relatively preserved ability to read aloud strings in which the assignment of the typical pronunciation for each component character yields the correct pronunciation for the whole word. The degree of consistency of character-sound correspondences affected his performance on both words and nonwords in a graded manner. One interpretation is that TI's surface dyslexic reading reflects intact direct computation of phonology from orthography, but without the additional constraint from word meaning that is, in this framework, considered critical for correct pronunciation of lower-frequency words with atypical character-sound correspondences. Another interpretation is that TI's performance reflects partially damaged lexical knowledge of whole-word orthography and phonology, coupled with spared sublexcal knowledge of character-sound correspondence rules. Whichever of these interpretations is preferred, this study offers the most detailed information yet available on the characteristics of surface dyslexia in Japanese.

Dementia↗
PubMed2003

Delayed-type hypersensitivity in sheep induced by synthetic peptides of bovine leukemia virus encapsulated in mannan-coated liposome.

Four sheep were immunized with synthesized peptides, derived from bovine leukemia virus (BLV) envelope glycoprotein, encapsulated in mannan coated liposomes as adjuvant. On the seventh day after the immunization, the sheep were intradermally challenged with BLV antigen, or synthesized peptides. The areas challenged with antigen were increased skin thickness and biopsied sequentially for immunohistological examinations. Strong delayed-type hypersensitivity was induced in sheep immunized and challenged with peptides encapsulated in mannan-coated liposomes. The major phenotype of the infiltrating lymphocytes was CD5(+). The ratio of CD4(+) to CD8(+) cells was about 1:1.

Adjuvants, Immunologic↗
PubMed2003

Relation between phenotype of tumor cells and clinicopathology in bovine leukosis.

Thirty-three cases of enzootic bovine leukosis (EBL) and 14 cases of sporadic bovine leukosis (SBL) were examined by immunohistochemistry using 6 monoclonal antibodies against leukocyte differentiation molecules of bovine leukocytes. There were 17 cases of B-1a cell type, 10 cases of B-1b cell type and 6 cases of B-2 cell type in EBL, and 5 cases originating from B cells (B-2 cell type) and 9 cases originating from immature T cells in SBL. The average age for the EBL cases of B-1a cell type was 8.6 years, B-1b cell type was 6.5 years, and of B-2 cell type was 4.5 years. In cases of SBL, immature T cell type patients were younger than B-2 cell type ones. The lymphoma originating from B cells differed from that originating from T cells in morphology. In T cell tumors, the nucleus of tumor cells was round, the edge of the cytoplasm obvious, and tumor cells were sporadically present and proliferated. When compared with T cells, the region among B cells was obscure. But, there was no relation between phenotype and the histologic classification of tumor cells. In EBL, beyond the lymph node, tumors of B-1a and B-1b types had developed in the heart and abomasum, and those of the B-2 type tended to occur in liver. In SBL, B-2 type and T type cells formed tumors in the liver, kidney, thymus, and one case of T-cell type tumor formed on the skin. We would like to propose a new classification of bovine leukosis as EBL, calf type B-cell lymphoma, juvenile T-cell lymphoma and skin type T-cell lymphoma.

Abomasum↗
PubMed2003

[The prevalence of mild cognitive impairment (MCI) among the community-dwelling elderly: findings from the 2nd Nakayama study].

To determine the prevalence of Mild Cognitive Impairment (MCI) in community dwelling elderly, a door to door population survey was carried out on all persons aged 65 years and older residing at home on the prevalence day (1 August 1999). All assessments were conducted by neuropsychiatrists. The diagnosis was made with the Geriatric Mental State (GMS)--Automated Geriatric Examination for Computed Assisted Taxonomy (AGECAT) (Copeland et al, 1986). AGECAT organicity levels 1 and 2 (sub-cases) are referred to as MCI. Of 1461 inhabitants, 1156 (79.1%) completed the protocol. The prevalence of MCI was 5.3%, with 1.7% organic brain syndrome level 2 and 3.6% organic brain syndrome level 1. MCI is associated with an increased risk of developing dementia. However, research on the prevalence of MCI has produced inconsistent data. The operational consensus criteria of MCI should be established for future community-based longitudinal study.

Age of Onset↗
PubMed2003

[Cotard syndrome].

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Anti-Anxiety Agents↗