Biomedical subjects

Y Aida

Publications and source records attributed to Y Aida.

At least 55 records · Page 3Linked to original sources

PubMed1997

Further analysis of the phenotype and distribution of tumor cells in sporadic B-cell and T-cell lymphomas in the lymph node and spleen of cattle.

Immunohistologic studies were performed to identify the phenotype and distribution of neoplastic lymphocytes in the spleens of BLV-negative animals examined by PCR and diagnosed as having sporadic bovine leukosis. Tumor cells from three cases of sporadic bovine leukosis were identified as of B-cell lineage. Tumor cells from three additional cattle were identified as CD3+ CD4- CD8+, CD3+ CD4- CD8-, and CD3+ CD4- WC1+, respectively. The last case was diagnosed as a gamma/delta T-cell lymphoma. Differences in morphology proliferative characteristics were recognized between B- and T-cell type lymphomas. The tumor cells in B-cell type lymphoma were characterized as follows: medium or large in size, round or polymorphic nucleus with rough chromatin with some tumor cells containing a convoluted nucleus. These tumor cells of B-cell type lymphoma were present in the red pulp and periarteriolar lymphoid sheath. Tumor cells of the T-cell type lymphoma were uniformly smaller than B-cell type and present around arteries or replaced red pulp of the spleen.

Animals↗

PubMed1997

A case of primary malignant fibrous histiocytoma of the heart with a left-to-right atrial shunt.

A previously healthy 64-year-old woman attended our hospital with chest pain, facial edema, and general fatigue. A chest radiograph revealed cardiomegaly, small bilateral pleural effusions, and hilar congestion--findings that improved after early therapy with furosemide and methyldigoxin. A chest radiograph recorded 7 years earlier had revealed no dilation of cardiac shadow. There were no findings suggesting atrial septal defect (ASD) or valvular heart disease. Echocardiography revealed a tumor-like mass adhering to the posterior wall of the left atrium. Color-flow Doppler echocardiography revealed a left-to-right shunt at the atrial level. The Qp/Qs ratio as measured by cardiac catheterization was 2.0. Coronary angiography revealed abnormal dilated arteries from the atrioventricular nodal branch and several feeding arteries from the left circumflex branch. We hypothesized that the left-to-right shunt could be due to the tumor, which extended to the rim of the patent foramen ovale, or to the very small, previously unrecognized, ASD. This patient died 6 months after her first admission and an autopsy was performed. Light microscopic examination of the tumor revealed spindle-shaped fibroblast-like cells arranged in a storiform or fascicular pattern. The immunohistochemical findings were consistent with malignant fibrous histiocytoma (MFH). In the literature, left-to-right shunt at the atrial level has not been reported in patients with cardiac MFH.

Echocardiography↗

PubMed1997

[Abducens palsy].

Explore the source record for details and available documents.

Abducens Nerve↗

PubMed1997

The role of tumor-associated antigen in bovine leukemia virus-induced lymphosarcoma.

Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis (EBL), which is the most common neoplastic disease of cattle. To clarify the way in which BLV-infected cattle progress from the asymptomatic stage to the lymphoma stage, we produced a monoclonal antibody (MAb) c143 which recognized a tumor-associated antigen (TAA) that is phosphorylated in the transformed state of BLV-infected B-lymphoid cells. Since the nature of c143 TAA was likely to be that of the major histocompatibility complex (MHC) class II antigens, we isolated cDNAs for bovine MHC (BoLA) class II a-chains and b-chains, produced transfectants that expressed a single type of BoLA class II molecules and analyzed them by flow cytometry with c143 MAb. The c143 MAb recognized the transfectant expressing BoLA-DR but not BoLA-DQ. However, the treatment of lymphocytes with c143 or anti-BoLA-DR MAb induced different effects. Although mixed lymphocyte reaction (MLR) was inhibited by the addition of anti-BoLA-DR MAb, the c143 MAb did not inhibit a proliferative response of T cells in MLR. Increased spontaneous proliferation of lymphocytes in healthy donors was obtained in the presence of c143 MAb but not anti-BoLA-DR MAb, and was much in lymphocytes from the carrier. Moreover, the patterns of immunohistological staining for c143 MAb in BLV-infected sheep showed distinguishing differences from those of anti-BoLA-DR MAbs.

Animals↗

PubMed1997

Tumor-associated antigen in lymph nodes during the progression of enzootic bovine leukosis.

A monoclonal antibody, (MAb) c143, that recognizes a tumor-associated antigen (TAA) that is upregulated on neoplastic B cells in cattle with enzootic bovine leukosis (EBL), was used as a marker to study disease progression. Immunohistochemical examination of neoplastic tissue and lymph nodes from animals with EBL, revealed three morphologically definable stages of change in the architecture of lymph nodes associated with infiltration and proliferation of neoplastic cells: 1) presence of c143 positive cells at the marginal sinus with no apparent changes in lymph node architecture at the earliest stage of neoplastic cell accumulation, 2) presence of positive cells extending into and distorting the architecture of the lymph node with clear evidence of proliferation, and 3) presence of positive cells throughout the lymph node with total disruption of lymph node architecture. The results indicated that, at the earliest stages of EBL, neoplastic cells in peripheral blood may accumulate at the marginal sinus area and subsequently proliferate and infiltrate pressing follicles leading to the development of clinical signs of lymphosarcoma.

Animals↗

PubMed1997

Point mutation of p53 tumor suppressor gene in bovine leukemia virus-induced lymphosarcoma.

To elucidate the mechanism of leukemogenesis induced by bovine leukemia virus (BLV), the abnormality of p53 tumor suppressor gene was examined using the sequencing method of polymerase chain reaction (PCR)-amplified DNA from peripheral blood lymphocytes (PBL) and tumors from BLV-infected cattle that showed evidence of different stages during the progression of enzootic bovine leukosis (EBL). Mutations of the p53 gene were found in tumor cells from cattle with EBL, but not in PBL from BLV-free normal cattle or BLV-infected cattle without any evidence of tumor, suggesting mutation of p53 gene occurred specifically at the lymphoma stage of the disease. Twelve of eighteen cattle with EBL had seven missense and five silent mutations. The mutations were mapped to the highly evolutionarily conserved regions of p53 gene, and were involved in the DNA binding of p53. Thus, it appeared that the p53 point mutation is one of the critical events leading from the asymptomatic stage to the lymphoma stage.

Animals↗

PubMed1996

Predominant p53 mutations in enzootic bovine leukemic cell lines.

The role of the p53 tumor suppressor gene in bovine lymphosarcomas, a fragment of about 100 bp corresponding to approximately 97% of the open reading frame of the p53 gene was first amplified from single-strand cDNA originated from calf thymus by polymerase chain reaction PCR) and sequenced to obtain the bovine wild-type p53 gene. At the amino acid level, the omologies of the bovine p53 gene with the human, mouse, chicken and cat p53 genes were 0.9%, 72.8%, 52.7% and 82.3%, respectively. Moreover, eight bovine leukemic cells lines were studied for alterations in the p53 gene. These lines showed no significant somatic alterations in southern blot analysis, and expressed 2.5 kb p53-specific transcripts in Northern blot analysis. In mutation analysis using the reverse transcriptase-PCR technique, we detected three missense point mutations in four of these bovine leukemic cell lines. These mutations occurred in the 'hotspots' of the p53 gene. Thus p53 mutations predominantly occur in BLV-transformed cell lines and seem to be necessary for development of enzootic bovine leukosis (EBL).

Amino Acid Sequence↗

PubMed1996

Identification of bovine invariant chain (Ii) gene by nucleotide sequencing.

Four overlapping cDNA clones encoding the bovine invariant chain (Ii) were isolated and characterized. The bovine Ii cDNA clone, NI3 with a 1,381-bp insert, encoded a translated product of 204 amino acids. The amino acid sequences deduced from this clone revealed that the bovine Ii gene is more closely related to human Ii gene than to genes for rodents, such as mouse and rat, but lacked 10 amino acids of the 3' end of the extracellular domain comparable to those in proteins from other species. Of interest is that the class-II-associated invariant chain peptide (CLIP) segment is present in the protein encoded by NI3, and this region exhibits a high degree of overall similarity to sequences encoded by human, mouse and rat, suggesting that bovine CLIP may have the biological function of CLIP binding to MHC class II molecules. Thus, it seems likely that this cDNA clone encodes a functional product which might perform an important function in MHC class II antigen presentation, as previously established in studies in mouse and man.

Amino Acid Sequence↗

PubMed1996

Inactivation of hepatitis C virus cDNA transgene by hypermethylation in transgenic mice.

Transgenic mice were produced by microinjection of a partial hepatitis C virus (HCV) genome sequence including the structural protein region, under the control of the albumin promoter and enhancer into fertilized eggs of C57BL/6 and BDF1 mice. Three founders carrying at least five copies of the transgene but not expressing HCV-specific RNA were generated. Methylation analysis indicated that the transgene was extensively methylated. Mapping of methylated cytosine residues of the transgenic mouse DNA showed that all C residues of a particular part of the HCV genome but not all the CpG island like sequences were methylated. Transiently expressed HCV cDNA in COS7 cells and the active endogenous albumin gene were not methylated. Furthermore, 5-azacytidine, a potent demethylating agent, induced HCV gene expression in a line of these transgenic mice. These results suggest that methylation of HCV cDNA is a cause of its inactive expression in transgenic mice, and that this phenomenon may occur in other stable systems for expression of the HCV genome.

Animals↗

PubMed1996

Lipopolysaccharides from Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans promote osteoclastic differentiation in vitro.

Bacterial lipopolysaccharides possess bone-resorbing activity. Here, lipopolysaccharides from three putative periodontopathic bacteria were examined for effects on osteoclast-like cell formation of bone marrow cells from lipopolysaccharide-responsive C3H-HeN and non-responsive C3H/HeJ mice. The bone marrow cells were cultured with or without various doses of lipopolysaccharide in the presence of 1,25-dihydroxyvitamin D3 and dexamethasone. These lipopolysaccharide preparations significantly increased the number of osteoclast-like cells formed in the culture of C3H/HeN marrow cells; the same as lipopolysaccharides from Escherichia coli and a synthetic lipid A with E. coli-type structure (LA-15-PP), at doses from 0.1 to 1 microgram/ml. This stimulating effect of each lipopolysaccharides was uniformly abrogated by the addition of polymyxin B at 5 micrograms/ml. All the lipopolysaccharide and the synthetic lipid A had no effect on osteoclast formation of the C3H/HeJ marrow cells, whereas lipopolysaccharide from Porphyromonas gingivalis and Prevotella intermedia showed significant mitogenic activity on C3H/HeJ spleen cells. It seems likely that the activity of lipopolysaccharides to augment osteoclast-like cell formation in the bone marrow cell cultures is derived from a common structure of the lipid A portion.

Acid Phosphatase↗

PubMed1996

Changes in the distribution of cells expressing tumour-associated antigen in lymph nodes during the progression of enzootic bovine leukosis.

A monoclonal antibody (MAb), c143, that recognizes a tumour-associated antigen that is "upregulated" on neoplastic B cells in cattle with enzootic bovine leukosis (EBL), was used as a marker to study disease progression. An immunohistochemical examination of neoplastic tissue and superficial cervical lymph nodes from 14 animals with EBL revealed three morphologically definable stages of change in the structure of lymph nodes, associated with the distribution of c143-positive cells: (1) the presence of c143-positive cells at the marginal sinus with no apparent changes in lymph node structure; (2) the presence of positive cells extending into and distorting the architecture of the lymph node, with clear evidence of proliferation before overt changes (enlargement of lymph nodes) were evident; and (3) the presence of positive cells throughout the lymph node with total disruption of lymph node structure when clinical signs of lymph node enlargement were evident. The results indicated that the bovine leukaemia virus-transformed lymphocytes or neoplastic cells in peripheral blood accumulate in the marginal sinus area at the earliest stages, and subsequently proliferate and infiltrate into follicles, leading to the development of clinical signs of lymphosarcoma.

Animals↗

PubMed1996

B-1a, B-1b and conventional B cell lymphoma from enzootic bovine leukosis.

In order to characterize the phenotypes of tumor cells and to clarify from which B cell lineage the lymphomas were derived, ten cows with enzootic bovine leukosis were examined by means of immunohistologic staining and flow cytometry. The tumor cells expressed mainly major histocompatibility complex (MHC) class II+ (10/10), BoCD11b+ (9/10), IgG1+ (8/10), B-B2+ (8/10) BoCD5+ (7/10), and lambda light chain+ (7/10). Tumor cells from only one animal expressed sIgM+ (1/10). Tumor cells from all ten animals were negative for IgG2, BoCD3, BoCD4, BoCD8, WC1-N2, and IL-2R alpha. The phenotypes of these tumor cells were all slightly different, suggesting that bovine leukemia virus (BLV)-induced lymphoma expresses phenotypic diversity. Moreover, tumor cells from seven cattle coexpressed BoCD5 and BoCD11b (B-1a cells). On the other hand, tumor cells from two of them only expressed BoCD11b (B-1b cells), and those from one were negative for both BoCD5 and BoCD11b (conventional B cells). Therefore, we concluded that BLV-induced lymphoma cells can be derived from B-1a, B-1b and conventional B cells.

Animals↗

PubMed1996

Isolation of alkaline phosphatase-positive gingival fibroblasts from patients with chronic inflammatory periodontal disease.

We have reported recently that increased expression of membrane alkaline phosphatase (ALP) activity is a phenotypical characteristic of gingival fibroblasts located in chronic inflammatory periodontal lesions. To understand the cellular properties of these cells, we isolated ALP-positive gingival fibroblasts from patients with adult periodontitis and evaluated their proliferative potential. Using an enzymatic digestion procedure, we prepared gingival cell suspensions containing ALP-positive fibroblasts without affecting their ALP activities. These cell suspensions were then subjected to 1 g sedimentation, followed by allowing cells to adhere to substrata. Using this procedure, 71.9% of isolated cells were ALP-positive. Dissociation of ALP-positive fibroblasts and contamination by non-fibroblastic cells were examined by cytochemical and immunocytochemical analyses. The proliferative capacity of ALP-positive fibroblasts in culture was assessed by monitoring the proportion of ALP-positive cells after repeated subculture passages and by labelling DNA-synthesizing cells with bromodeoxyuridine (BrdU). The proportion of ALP-positive fibroblasts decreased during cell culture passages without an apparent change in the ALP-positive phenotype. The percentage of BrdU-positive cells was significantly lower among ALP-positive than among ALP-negative fibroblasts. These results indicate that ALP-positive fibroblasts in chronic inflammatory periodontal lesions have low growth potential. We suggest that their reduced capacity to grow in vitro reflects a more differentiated state induced under inflammatory conditions in vivo.

Adult↗

PubMed1996

Synthesis of 7-methoxyapigeninidin and its fungicidal activity against Gloeocercospora sorghi.

In the structure of sakuranetin, which was isolated as a phytoalexin from the rice plant, the methoxy group at C-7 has been shown to be important for its high activity. Apigeninidin was isolated as a phytoalexin from sorghum, but it had no methoxy group at C-7. We prepared 7-methoxyapigeninidin and compared its fungicidal activity with that of apigeninidin. The 7-methoxyapigeninidin showed higher activity against sorghum fungi than apigeninidin, suggesting that the methoxy group at C-7 was important for the high fungicidal activity.

Anthocyanins↗

PubMed1996

Correlation between intrasinusoidal neutrophilic infiltration and ceroid-lipofuscinosis in alcoholic liver fibrosis with or without fatty change: clinicopathological comparison with nutritional fatty liver.

A histopathological study was conducted on alcoholic liver fibrosis with fatty change (21 cases) and alcoholic liver fibrosis without fatty change (18 cases) in comparison with nutritional fatty liver (27 cases). The diagnoses of alcoholic liver fibrosis groups were clinically fulfilled according to the criteria established by the Alcohol and Liver Research Group (Chief: Professor Takeuchi) of the Ministry of Education of Japan. Histological diagnosis of alcoholic liver fibrosis with fatty change was based on moderate and/or greater fatty metamorphosis of the hepatic lobules, alcoholic liver fibrosis without fatty change on a lesser degree of fatty metamorphosis than alcoholic liver fibrosis with fatty change, and nutritional fatty liver on clinicopathological features. All 66 cases were negative for viral markers of hepatitis B surface antigen and anti-hepatitis C virus in serum. Intrasinusoidal neutrophil infiltrations were significant in cases of alcoholic liver fibrosis groups more often than in cases of nutritional fatty liver. The degree of intrasinusoidal neutrophil infiltration in cases of alcoholic liver fibrosis groups was higher in cases who had last consumed alcohol recently, compared with those with longer abstinence. In alcoholic liver fibrosis with fatty change and nutritional fatty liver groups, mild-to-moderate degrees of ceroid-lipofuscinosis were recognized, but both fatty change and ceroid-lipofuscinosis were decreased according to the deterioration of fibrotic changes in alcoholic liver fibrosis with fatty change cases. On the other hand, it is significant that the frequency of ceroid-lipofuscinosis in alcoholic liver fibrosis without the fatty change group was lower than those of the alcoholic liver fibrosis with fatty change and nutritional fatty liver groups. Distribution of ceroid-lipofuscinosis has a tendency to be recognized around the central zone (zone III) of alcoholic liver fibrosis with fatty change cases with mild fibrosis, as in nutritional fatty liver cases, and the ceroid-lipofuscinosis disperses with the progression of fibrosis. These results suggest that fibrosis and fatty droplet deposition lead to microvascular heterogeneity. Therefore, the degree and distribution of fatty droplets, ceroid-lipofuscinosis, and intrasinusoidal neutrophil infiltration differ, depending on the etiology of fatty liver, and are an important histopathological barometer in cases of alcoholic liver fibrosis with fatty change and alcoholic liver fibrosis without fatty change, thus indicating the degree of fibrosis and the period since last alcohol intake.

Adult↗

PubMed1995

Nucleotide sequences and the molecular evolution of the DMA and DMB genes of the bovine major histocompatibility complex.

cDNA clones encoding the bovine major histocompatibility complex (MHC) class II DM alpha- and beta-chains were isolated and characterized. The BoLA-DMA cDNA clone, MA7, encoded a primary translated product of 260 amino acids, which included a signal peptide of 26 amino acids and a mature polypeptide of 234 amino acids. The BoLA-DMB cDNA clone, MB6, encoded a primary translated product of 262 amino acids, with a signal peptide of 18 amino acids and a mature polypeptide of 244 amino acids. Comparison of the sequences and construction of a phylogenetic tree revealed that both clones are more closely related to human and mouse DM genes than to genes for conventional bovine class II alpha- and beta-chains. Thus, since the bovine DMA and DMB genes are so different from other class II sequences and show evidence of strong conservation (> 70%) among the bovine, mouse and human homologues, it seems likely that each of these cDNA clones encodes a functional product, which might perform an important function, as previously established in studies in mouse and man.

Amino Acid Sequence↗

PubMed1995

Thrombopoietin induces megakaryocyte differentiation in hematopoietic progenitor FDC-P2 cells.

Thrombopoietin (Tpo) is a cytokine that specifically regulates megakaryocyte maturation and platelet production. Little is known about the molecular and cellular mechanism of the Tpo-induced megakaryocyte maturation process including polyploidization and platelet release. To study Tpo-induced megakaryocyte differentiation, a mouse cell line FD-TPO, which responds and grows with Tpo, was established from a interleukin-3-dependent hematopoietic progenitor cell line FDC-P2. The FD-TPO cells, expressing endogenous Tpo receptor, grew with Tpo in a dose-dependent manner. Further, Tpo stimulation dramatically induced expression of megakaryocyte/erythroid-specific transcription factors GATA-1 and NF-E2 in FD-TPO cells. Flow cytometry analysis demonstrated that expression of platelet-specific cell surface antigens including CD61 (GPIIIa) dramatically increased in Tpo-stimulated FD-TPO cells and that expression of myeloid-specific antigens, Gr-1 and Mac-1, decreased. Therefore, we concluded that the binding of Tpo to FD-TPO cells induces not only cell growth but also differentiation into mature megakaryocyte-like cells, and thus this cell line was found to be useful for the study of Tpo receptor-mediated growth and differentiation signals.

Animals↗

PubMed1995

Nucleotide sequence and the molecular evolution of a new A2 gene in the DQ subregion of the bovine major histocompatibility complex.

cDNA clones encoding the bovine major histocompatibility complex (MHC) class II DQ alpha chain were isolated. One clone, MQ9, encoded a primary translated product of 255 amino acids, with a signal peptide of 23 amino acids and a mature polypeptide of 232 amino acids. A new A2 gene in the DQ subregion of the bovine genome was identified from a comparison of amino acid sequences encoded by class II A genes among several species and the construction of a phylogenetic tree. It was revealed that MQ9 is most closely related to the ovine DQA2 genes among sequences from various mammalian species. By contrast, the BoLA-DQA genes previously isolated are more closely related to ovine DQA1 than to the BoLA-DQA2 gene, and they represent BoLA-DQA1 genes. Thus, the presence of two BoLA A genes, which may be expressed and functional in the bovine, as well as in sheep was confirmed. A large number of amino acids unique to products of DQA2 genes of bovine and ovine origin were identified when the predicted amino acid sequences for both species were compared, and most of the DQA2-specific residues were located in the alpha 1 domain and were conserved with respect to products of DQA1 genes of ruminants. Thus, several characteristics of the bovine DQA genes were found to differ from those of human and rodent genes, despite similarities in gene structure and in nucleotide sequence.

Amino Acid Sequence↗