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Biomedical subjects

Y Yasuda

Publications and source records attributed to Y Yasuda.

At least 109 records · Page 6Linked to original sources
PubMed1998

Advanced glycation end products co-localized with astrocytes and microglial cells in Alzheimer's disease brain.

In the previous study [Takeda et al. (1996) Neurosci Lett 221: 17-21], we reported that the advanced glycation end products (AGEs) in the external space of neuronal perikarya (extraneuroperikaryal AGE deposits) were significantly abundant in the Alzheimer's brain. In this study, we investigated the spatial relationship of the extraneuroperikaryal AGE (carboxymethyllysine and pentosidine) deposits in astrocytes and microglial cells in the Alzheimer's disease brain using double immunolabelling for AGEs and astrocyte or microglial cell markers. Most of the extraneuroperikaryal AGE deposits were co-localized with glial fibrillary acidic protein-positive astrocytes. AGE deposit-bearing astrocytes also contained Gomori-positive granules. Furthermore, some of the extraneuroperikaryal AGE deposits were co-localized with microglial cells. These extraneuroperikaryal AGEs may activate astrocyte and microglia, and play a role in pathogenesis of Alzheimer's disease.

Aged↗
PubMed1998

Cloning and chromosomal mapping of the human gene of neuroglycan C (NGC), a neural transmembrane chondroitin sulfate proteoglycan with an EGF module.

Neuroglycan C (NGC) is a 150 kDa transmembrane chondroitin sulfate proteoglycan with a 120 kDa core glycoprotein that was originally isolated from the developing rat brain. A rabbit antiserum, raised against a recombinant polypeptide representing a protein of the rat NGC core protein, recognized an NGC homolog in homogenates of brains of various vertebrates including humans. Because of the possible involvement of this proteoglycan in the etiology of a human neuronal disease, we cloned a complete coding sequence from a human brain cDNA library using a rat NGC cDNA as a probe. The predicted protein contains 539 amino acids and shows 86% homology with the rat counterpart. The domain structure characteristic of rat NGC was completely conserved in human NGC, which consisted of an N-terminal signal sequence, a chondroitin sulfate-attachment domain, an acidic amino acid cluster, an EGF-like domain, a transmembrane domain and a cytoplasmic tail. Northern blot analysis revealed that a single transcript of 2.4 kb was detectable in the brain, but not in other human tissues. By fluorescence in situ hybridization (FISH) analysis, the human NGC gene was assigned to the chromosomal 3p21.3 band, where the Sotos syndrome has been mapped. Involvement of the NGC gene in the etiology of the Sotos syndrome remains to be examined.

Amino Acid Sequence↗
PubMed1998

Systemic and mucosal immune responses of mice to aluminium-adsorbed or aluminium-non-adsorbed tetanus toxoid administered intranasally with recombinant cholera toxin B subunit.

For the purpose of changing the immunization procedure of tetanus toxoid from intramuscular or subcutaneous injection, which has been in practice for a long time, to intranasal administration, we examined systemic and mucosal immune responses of mice to aluminium-adsorbed tetanus toxoid (aTT) and aluminium-non-adsorbed tetanus toxoid (nTT) inoculated intranasally with recombinant cholera toxin B subunit (rCTB). Intranasal immunization with aTT induced, at a concentration of 0.5 Lf, high levels of TT-specific serum IgG antibody titres and moderate levels of TT-specific serum IgA antibody titres in the presence and absence of rCTB. Induction of high or moderate levels of mucosal TT-specific IgA antibody responses was observed with and without rCTB in the lung, the nasal cavity, the small and large intestines and the vagina. Generally speaking, the co-administration of aTT and rCTB showed higher mucosal TT-specific IgA antibody titres when compared with the administration of aTT alone. In case of intranasal administration of nTT, the dose of 5 Lf was necessary and stimulated, only in the presence of rCTB (10 micrograms), high levels of tetanus toxoid (TT)-specific serum IgG antibody responses in all mice examined and moderate or slight levels of TT-specific IgA antibody responses in the nasal, pulmonary and small and large intestinal lavages of a few mice. All mice intranasally immunized with aTT alone or nTT and rCTB escaped onset of tetanus. This is the first report concerned with the mucosal adjuvant activity of an aluminium compound. Judging from these results, intranasal administration of aTT with and without rCTB or nTT with rCTB appears to be a very useful means for a vaccination against tetanus with respect to ease, safety, certainty, low cost and no need for an injection needle.

Administration, Intranasal↗
PubMed1998

Excitotoxin-induced neuronal death is associated with response of a unique intracellular aspartic proteinase, cathepsin E.

Excitotoxicity produced by excessive stimulation of glutamate receptors is known to lead to neuronal lesion and death. Here, we demonstrate that quantitative and qualitative changes in cathepsin E (CE) gene products are associated with execution of the excitotoxic neuronal death. Intracerebroventricular injection of kainate (KA) resulted in marked elevation of both mRNA and protein levels of CE in the rat hippocampal CA3 region, where the enzyme was mainly found in vulnerable neurons and activated microglia. Northern blot analysis showed that the size of the transcript for CE was identical with that normally expressed in rat spleen. Immunoblot analysis, however, revealed the predominant occurrence of the highly modified CE species, besides the mature CE. This polypeptide was distinct from the mature CE in molecular masses (106 vs. 82 kDa) and pI (6.4-7.3 vs. 5.0-5.5) and showed resistance to conversion into the enzymatically active form by acid treatment. Consistent with these in vivo results, administration of glutamate to primary cultured rat hippocampal neurons resulted in a marked expression of this novel CE species. These data indicate that excessive stimulation of glutamate receptors causes induction of the CE gene response followed by persistent expression of CE in the novel form, besides its mature form, predominantly in the hippocampal neurons.

Animals↗
PubMed1998

Functional quantitative analysis of the genome in cultured human mesangial cells. Technical note.

For normal physiological function, each cell tightly regulates gene expression in a specific fashion so that critical proteins are synthesized in a well-coordinated manner. Therefore, it is very important to uncover which genes are expressed in specific cells. Recent technological advances combined with rapid large-scale DNA sequencing and computerized data processing have allowed us to investigate the expression levels of a variety of transcripts in the mesangial cells, a target of injury in many forms of glomerulonephritis. Utilizing a large scale sequencing of a 3'-directed cDNA library, which allows us to avoid variable cloning efficiencies reflecting the size of cDNA, we investigated expression profiles of various molecules in cultured human mesangial cells. Among the 1,193 sequenced clones, 688 (57.7%) appeared more than once (redundant sequence group), representing 203 different species. Thirty-nine of these appeared more than three times. The most abundant mRNA was that of fibronectin, which consisted of 3.9% of the total mRNA population. Except for mitochondrial or ribosomal genes, calcyclin came next (2.5%), followed by two cytoskeletal genes, gamma-actin gene and calpactin 1 light chain gene, in addition to an amyloid precursor protein homolog (0.7%). In conclusion, we performed a molecular biological quantification of transcripts in mesangial cells. Fibronectin was the most abundantly expressed, followed by calcyclin, gamma-actin, calpactin 1 light chain, and an amyloid precursor protein homolog. We also discovered some candidate genes specific for human mesangial cells. The expression profile of the transcripts serves as an important tool in understanding the biological properties of mesangial cells.

Actins↗
PubMed1998

Donor primordial germ cell-derived offspring from recipient germline chimaeric chickens: absence of long-term immune rejection and effects on sex ratios.

1. Germline chimaeric chickens were produced by the transfer of primordial germ cells, and the generation of donor-derived offspring was examined for a maximum of 146 weeks. 2. The frequencies of donor-derived offspring from the chimaeras were 47% to 97%, and no apparent changes in frequency were observed with increasing age during the test period. 3. Differentiation of donor primordial germ cells into functional gametes appeared to be restricted to a degree at some developmental stage in the gonads of chimaeric chickens of the opposite sex.

Animals↗
PubMed1998

Affinity purification of recombinant cholera toxin B subunit oligomer expressed in Bacillus brevis for potential human use as a mucosal adjuvant.

For use as a mucosal adjuvant for human vaccines, a simple method has been developed for the affinity purification of recombinant cholera toxin B subunit which had been expressed in a safe host, Bacillus brevis. Recombinant cholera toxin B subunit, adsorbed quantitatively to a D-galactose-agarose column, was eluted with an 0.1-0.4 M D-galactose gradient with a yield of > 90%. The cholera toxin B subunit preparation was similar to the native cholera toxin B subunit with respect to GM1 binding ability, remarkable stability of the pentamer, and the dissociation-reassociation property by shifting pHs. Cross-linking experiments with glutaraldehyde demonstrated that the pentameric form was predominant; tetrameric, trimeric, dimeric and monomeric forms were detected to a lesser extent, and additionally 10- and 15-mers were observed depending on the concentration of the cholera toxin B subunit.

Adjuvants, Immunologic↗
PubMed1998

Supplementation effect of early pregnancy factor-positive serum into bovine in vitro fertilization culture medium.

PROBLEM: Early pregnancy factor (EPF) has been detected in pregnant bovine serum, and its activity appeared from 24 to 48 hr after insemination. However, in bovine in vitro fertilization (IVF), an EPF-like substance(s) had been detected in the culture medium of fertilized ovum. Therefore, we think that EPF and EPF-like substance(s) are very important materials for the development of the embryo. In this study, we examined the development of the embryo when fertilized bovine ova were cultured with IVF culture medium supplemented with EPF-positive or -negative serum. METHOD OF STUDY: EPF activity of each serum (fetal calf serum [FCS], calf serum [CS], estrus bovine serum, and pregnant bovine serum) was assessed by the bovine-rosette inhibition test. The sera were supplemented in TCM-199 culture medium, and IVF bovine ova were cultured with the media for 6 or 7 days, respectively. The culture media of each group were evaluated for EPF activity by the bovine-rosette inhibition test 48 hr after IVF. The cleavage rate of each group was calculated at 48 hr, and 6 or 7 days after IVF. The culture medium of cumulus cells was also tested for EPF activity. RESULTS: Only the pregnant bovine sera were EPF positive. All the culture media 48 hr after IVF became EPF positive. Additionally, the culture medium of cumulus cells did not have EPF activity. There was no significant difference in the cleavage rate of the EPF-positive and -negative sera 48 hr after IVF. However, the cleavage rate of EPF-positive sera tended to be higher than the negative sera. In contrast, the blastocyst development rates of EPF-positive sera were significantly higher than those of the negative sera 6 to 7 days after IVF (P < 0.05). CONCLUSIONS: The data suggest that an EPF-like substance(s) may be secreted from the in vitro fertilized bovine ovum but not from the cumulus cell, and that the EPF in the pregnant serum may accelerate the development of the bovine embryo in IVF.

Animals↗
PubMed1998

Bronchial asthma induced by rice.

A 43-year-old patient with rice-induced bronchial asthma was first admitted to our hospital for developing bronchial asthma induced by mite and house dust. At that time, there was no sign of allergic response to rice. Two years later, he was readmitted in an emergency state, with a severe attack of bronchial asthma. This time, however, the result of immunoglobulin E (IgE)-radioallergosorbent test (RAST) for rice was positive, with those to mite and house dust were unexpectedly negative. The causative factors and pathological mechanisms of various kinds of food allergies still remain unknown. The patient is now followed up in an ambulatory setting, and has been eating hypoallergenic rice with no bronchial asthma-induced attack. The present case, being an adult patient with severe grain-induced bronchial asthma previously allergic to mite and house dust, seems to be rather rare in the literature.

Adult↗
PubMed1998

Localizing value of bilateral cheiro-oral sensory impairment.

We present a case of bilateral cheiro-oral syndrome with paresthesia in the right toes following pontine infarction. The causative lesions were situated in the bilateral paramedian pontine tegmentum (PPM). As the lesion on the left side was larger than that on the right, the foot area in the left medial lemniscus was involved, causing paresthesia in the right toes. Bilateral cheiro-oral sensory impairment is rare, and there have been only 4 previous reports. The responsible lesion of complete bilateral cheiro-oral syndrome showing paresthesia in the hand and mouth region on both sides is in the bilateral PPM, while that of incomplete bilateral cheiro-oral syndrome showing paresthesia around both sides of the mouth and in the unilateral hand is in the PPM contralateral to the hand with paresthesia. Bilateral cheiro-oral sensory impairment can occur only in the brainstem.

Cerebral Infarction↗
PubMed1998

[Limited operation for stage I lung cancer: a retrospective study].

Although lobectomy is standard therapy for Stage I non-small cell lung cancer, it often cannot be performed in poor-risk patients. In this report, we describe the results of a retrospective study to assess the usefulness of limited operation for stage I lung cancer. Over a 21-year period, 1,286 lung cancers were resected at our center. Among the 497 patients with stage I lung cancer, 36 sublobar resections were performed. There was only one surgery-related death, and the 5-year survival rate was 46% for all patients. At 5 years, survival was 69.2% for patients with squamous cell carcinoma and 33.7% for patients with adenocarcinoma. Survival rates were higher in patients who underwent mediastinoscopy than those who did not, and depended on histological findings and accurate pathological staging.

Adenocarcinoma↗
PubMed1998

[A pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium].

We encountered a case of pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium. A 73-year-old woman was admitted to the hospital because a chest x-ray film showed enlargement of an abnormal shadow in the middle lobe of the right lung. Primary lung cancer was suspected and right middle lobectomy was performed. Acid-fast bacilli (Gaffky 1) were found in a caseous lesion and examination of intraoperatively obtained frozen specimens showed caseous granulomas. The bacilli were later identified as Mycobacterium avium complex. The permanent specimen showed a minute lesion consisting of small clusters of epithelial cells resembling carcinoid tumor in contact with granulomatous tissue. Histopathological examination revealed argyrophilia on Grimelius stain and immunoreactivity to chromogranin-A in the clusters of epithelial cells. Although these results are consistent with small cell carcinoma or peripheral carcinoid tumor, pulmonary tumorlet was diagnosed because of the lesion's small and minimal cytologic atypia, and because of chronic pulmonary damage around the lesion. Pulmonary tumorlets are minute, usually microscopic, tumor-like lesions mostly found in damaged lung tissue obtained at autopsy or during surgery. Morphological diagnosis is sometimes very difficult, but recently these lesions have been regarded as hyperplastic lesions arising in pulmonary neuroendocrine cells (Kultschitzky cells) and caused by chronic pulmonary damage, such as hypoxia and inflammation. Pulmonary tumorlets must be considered in the differential diagnosis of minute lesions suspected to be small cell carcinoma or peripheral carcinoid tumor.

Aged↗
PubMed1998

Concurrent generation of nitric oxide and superoxide inhibits proteoglycan synthesis in bovine articular chondrocytes: involvement of peroxynitrite.

OBJECTIVE: Nitric oxide (NO), widely assumed to be a mediator of interleukin 1 (IL-1), inhibits proteoglycan synthesis in articular chondrocytes. IL-1 also produces superoxide anion. We hypothesized that the IL-1 inhibited proteoglycan synthesis is the result of peroxynitrite formed by the reaction of NO with superoxide. METHODS: Bovine articular chondrocytes were cultured in the presence of SIN-1, which leads to simultaneous generation of both NO and superoxide. Proteoglycan synthesis was measured based on the incorporation of [35S] sulfate, and the presence of peroxynitrite was confirmed using immunohistochemistry. RESULTS: SIN-1 inhibited proteoglycan synthesis and superoxide dismutase reversed SIN-1 inhibited proteoglycan synthesis, indicating the simultaneous generation of superoxide is essential to inhibit proteoglycan synthesis. IL-1 induced peroxynitrite in articular chondrocytes and addition of peroxynitrite inhibited proteoglycan synthesis. CONCLUSION: The concurrent generation of superoxide anion and NO is required for the action of IL-1 to inhibit proteoglycan synthesis. Peroxynitrite is a candidate for this underlying mechanism.

Animals↗
PubMed1997

Unusual sensory disturbance in the thoracic region after stroke: relationship to cheiro-oral and cheiro-oral-pedal syndrome.

Three patients with unusual unilateral sensory disturbances in the thorax, in addition to hand and mouth, hand and foot, and hand, mouth and foot regions, respectively, after stroke, are described. Magnetic resonance imaging (MRI) showed a causative lesion in the ventral posteromedial and ventral posterolateral nucleus of the contralateral thalamus in two patients and the contralateral thalamocortical projections in one patient. Symptoms in three patients were due to infarction. Objective sensory loss was not found, but subjective paresthesia was observed in the thorax, in addition to the hand and mouth, hand and foot, and hand, mouth and foot regions, respectively. Paresthesia recovery time was evaluated in these three patients in addition to seven patients with cheiro-oral syndrome and eight patients with cheiro-oral-pedal syndrome. All thirteen patients who demonstrated recovery showed regional improvement of paresthesia in the following sequences: thorax, foot, mouth and then hand, which suggests that the detection threshold, from highest to lowest, occurs in the following sequences: thorax>foot>mouth>hand. These three cases with thoracic sensory disturbance form the explanatory links between the cheiro-oral syndrome and the cheiro-oral-pedal syndrome; cases with sensory disturbance in the hand, mouth, foot or thorax could be regarded as cases of sensory hemisyndrome in which the subjective experience of symptoms was restricted to the hand, mouth, foot or thorax. These symptoms may possibly be attributable to differential detection thresholds.

Aged↗
PubMed1997

Immunohistochemical localization of advanced glycation end products, pentosidine, and carboxymethyllysine in lipofuscin pigments of Alzheimer's disease and aged neurons.

Lipofuscins are intracellular fluorescent pigments accumulating in the central nervous system (CNS) with aging and degenerative processes such as Alzheimer's disease (AD). Although they are thought to be lipid peroxidation products derived from malondialdehyde, their biogenesis remains controversial. We further characterize the chemical nature of lipofuscins in brain tissues from AD patients and normal aged subjects. Advanced glycation end products (AGEs), pentosidine and carboxymethyllysine (CML), were identified by appropriate specific antibodies. They have physicochemical properties similar to those of lipofuscin and also increase with aging. Pentosidine and CML were identified in the neuronal perikarya and the extraneuroperikaryal deposits of both the AD and aged brain. Pentosidine, but not CML, was present in the fiber-like structure within the neuropil and the core of classical senile plaque. In the brain of young subjects without CNS disease, pentosidine and CML staining was faint. Pentosidine and CML co-localized with lipofuscin pigments in the neuronal perikarya of both the AD and aged brain. We demonstrate for the first time that lipofuscin is constituted not only of lipid peroxidation products but also from glycation products which may be the origin of fluorescent pigments. Lipofuscins should thus be considered as fluorescent pigments generated by lipid- and sugar-derived Schiff base-protein polymers.

Adolescent↗
PubMed1997

Localization of germination-specific spore-lytic enzymes in Clostridium perfringens S40 spores detected by immunoelectron microscopy.

The localization of germination-specific spore-lytic enzymes, an amidase and a muramidase, in Clostridium perfringens S40 spores was examined by immunoelectron microscopy with respective antisera raised against the enzymes and a colloidal gold-immunoglobulin G complex. For both antisera, immunogold particles were visualized on the outside of the cortex of dormant spores, and they were not detected in germinated spores and decoated spores.

Antibodies, Fungal↗