Biomedical subjects

E Sato

Publications and source records attributed to E Sato.

At least 163 records · Page 9Linked to original sources

PubMed1998

A subcloned human esophageal squamous cell carcinoma cell line with low thrombomodulin expression showed increased invasiveness compared with a high thrombomodulin-expressing clone--thrombomodulin as a possible candidate for an adhesion molecule of squamous cell carcinoma.

Thrombomodulin (TM) is an endothelial cell surface glycoprotein which converts thrombin from a procoagulant protease to an anticoagulant. We have previously reported that TM is a useful marker for immunohistochemical diagnosis of angiogenic tumors and also have reported that TM is expressed on squamous cell carcinoma (SCC) of the human esophagus. In addition, the expression of TM is significantly decreased in metastatic foci in lymph nodes compared with that in primary lesions. In order to reveal the biological significance of TM in SCC, we subcloned and established two different cell lines, i.e. TM-high-expressing (TE3HTM) cells and TM-low-expressing (TE3LTM) cells, from a human SCC cell line, TE3, using fluorescence-activated cell sorter (FACS) and examined the biological characteristics of these variant cell lines. These tumor cells revealed very similar morphological figures in ordinary cultured conditions and showed almost equal growth rates under various cultured conditions. By the invasion assay of these tumor cells using matrigel, we found that TE3LTM cells showed significantly increased invasive ability compared with that of TE3HTM cells. Characteristic intercellular localization of TM and a different manner of invasiveness between TE3LTM cells and TE3HTM cells suggest that TM may act as a cell-to-cell interaction molecule.

Carcinoma, Squamous Cell↗

PubMed1998

Adaptation of visually guided behavior during reversed vision in schizophrenia: a preliminary study.

This preliminary study evaluated the adaptation of visually guided behavior to reversed vision in schizophrenia. The study included 54 patients who met DSM-III-R criteria for schizophrenia. Visuomotor reaction times (VRTs) during reversed vision were measured in six blocks of 35 consecutive trials. The VRTs of schizophrenics were compared with those of normal subjects. A good fit (R2 = 0.9981) for the adaptation process of VRTs during reversed vision was found with the equation y = 1030 + 1499/x, where x is the order of the block and y is the group mean VRT for each block. The VRTs in schizophrenics were significantly slower than those in normal subjects. However, the adaptation process to reversed vision essentially did not differ from normal. The adaptation of visually guided behavior during reversed vision may involve procedural learning; this task may thus be useful in evaluating such learning. The VRTs during reversed vision may be related to some aspects of symptoms in the patient with schizophrenia and may also be useful in predicting clinical outcome.

Adult↗

PubMed1998

Midkine exists in astrocytes in the early stage of cerebral infarction.

Midkine (MK), a heparin-binding neurotrophic factor, is expressed in the early stage of experimental cerebral infarction in the zone surrounding the infarct. Double immunostaining with anti-MK and anti-glial fibrillary acidic protein showed existence of MK in astrocytic cytoplasm on postoperative day 2. Immunoelectron microscopic analysis revealed the presence of MK in the swollen astrocytic processes on postoperative day 4.

Acute Disease↗

PubMed1998

Expression of murine novel zinc finger proteins highly homologous to Drosophila ovo gene product in testis.

We have cloned two isoforms of cDNAs encoding novel zinc finger proteins. One form encodes a 274-amino acid protein containing an acidic amino acid and serine-rich domain and a zinc finger domain which shows high sequence homology to that of Drosophila Ovo protein. The other form encodes a 179-amino acid protein containing only the zinc finger domain. Expression of both proteins possessing an antigenic epitope in COS cells revealed that they are localized in the nucleus. The 1.3-kbp mRNAs are predominantly expressed in testis, and the expression increases from 3 weeks postnatal, implying that these proteins may play important roles in the development of the testes.

Amino Acid Sequence↗

PubMed1998

MAP kinase cascade, but not ERKs, activated during early cleavage of mouse embryos.

Mitosis in early embryos is independent of exogenous mitogens, although mitogen stimulations and subsequent activation of a mitogen-activated protein (MAP) kinase cascade are essential for the proliferation of somatic cells. The activation state of the MAP kinase cascade during early cleavage has never been reported. In the present study, factors involved in the MAP kinase cascade--Ras, Raf-1, 14-3-3, MEK, and ERKs--and their activation states were detected by immunoblotting during early cleavage of mouse embryos. We found the constant presence of these molecules in mouse early embryos and the activation of Raf-1 exclusively at the M-phase. An immunoprecipitation study revealed that active Raf-1 in the M-phase was dissociated from 14-3-3, as in somatic cells, whereas inactive Raf-1 was associated with 14-3-3. Surprisingly, the ERKs (MAP kinases) were not activated throughout early cleavage, although M-phase-specific activation of the MAP kinase kinase, MEK was observed. Myelin basic protein kinase activity was, however, significantly higher in the M-phase than in the interphase. These results indicate that the MAP kinase cascade is activated at the M-phase and that some MAP kinases other than ERKs are activated during early cleavage of mouse embryos.

14-3-3 Proteins↗

PubMed1998

Rapid detection of male-specific DNA sequence in bovine embryos using fluorescence in situ hybridization.

An accurate, reliable, and quick (less than an hour) method for determining the sex of bovine embryos was developed using a fluorescence in situ hybridization (FISH), with a probe designed from a bovine Y chromosome specific DNA (BC1.2). First, to improve a protocol of FISH and evaluate an accuracy of the method, lymphocyte nuclei prepared from three bulls, two cows, and one freemartin were tested. We found that 5 min was enough for hybridization. The washing solution adequate for posthybridization was 0.5x SSC at 72 degrees C for 5 min. The whole procedure for FISH can be accomplished in less than an hour. A male-specific signal was detected, on average, as 97, 0.5, and 83%, respectively, of lymphocytes in males, females, and a freemartin. Using the rapid FISH protocol developed, 28 embryos were divided. According to the presence of the digoxigenin signal, 16 embryos (57.1%) were predicted as male, and 12 embryos (42.9%), predicted as female.

Animals↗

PubMed1998

Perivascular T cells are infected with HTLV-I in the spinal cord lesions with HTLV-I-associated myelopathy/tropical spastic paraparesis: double staining of immunohistochemistry and polymerase chain reaction in situ hybridization.

HTLV-I-infected cells play an important role in pathogenesis HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Our previous studies of quantitative polymerase chain reaction (PCR) and in situ PCR suggested that T cells infiltrating in the spinal cord lesion were infected with HTLV-I. To elucidate the localization of HTLV-I proviral DNA directly, we performed double staining using immunohistochemistry and PCR in situ hybridization (PCR-ISH). Fresh frozen sections of the spinal cord from four HAM patients taken at autopsy were first immunostained with antibodies to pan T cells (UCHL-1), macrophages (KP-1) and helper/inducer T cells (OPD4). Then PCR-ISH was carried out with specific primers and probe for the HTLV-I pX region. UCHL-1-positive cells were noted around perivascular areas and, to some extent, in the parenchyma. Of the UCHL-1-positive cells, 9.4% (case 1), 9.6% (case 2), 1.1% (case 3) and 6.7% (case 4) became positive in HTLV-I PCR-ISH. UCHL-1-negative cells were HTLV-I PCR-ISH negative and almost all KP-1-positive cells were HTLV-I negative. HTLV-I was localized to OPD4-positive cells in examined lesions of cases 2 and 4. These data are a direct demonstration of HTLV-I proviral DNA localizing to infiltrated T cells in HAM/TSP spinal cord lesions.

Aged↗

PubMed1998

Preparation of a conjugate of mitomycin C and anti-neural cell adhesion molecule monoclonal antibody for specific chemotherapy against biliary tract carcinoma.

To develop a specific chemotherapy modality for the perineural invasion of neural cell adhesion molecule (NCAM) positive biliary tract cancer, an anticancer drug, mitomycin C (MMC), was covalently bound to anti-NCAM monoclonal antibody (anti-NCAM MoAb) to form a conjugate using the cyanogen bromide method. The substitution ratio of the conjugate determined spectrophotometrically was 3.5 (MMC mol/immunoglobulin G mol). The cytotoxic activity of the conjugate, which was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test in the growth inhibition of the neuroblastoma cell line with NCAM expression, was maintained at 65.8% to 94.5% compared with the same concentration of MMC solution. The binding activity of the conjugate to the NCAM-positive bile duct cancer was examined by immunohistochemical staining and proved to be the same level as that of free anti-NCAM MoAb. The conjugate prepared in this study therefore appeared to be a potentially useful tool for immunotargeting specific chemotherapy against biliary tract cancer with NCAM expression.

Antibiotics, Antineoplastic↗

PubMed1998

Cross virus neutralizing antibodies against feline immunodeficiency virus genotypes A, B, C, D and E.

Feline immunodeficiency virus (FIV) is classified into five genotypes, A, B, C, D and E, based on the phylogenetic analysis of the env V3-V5 region. However, whether there is correlation between phylogenetic and antigenic diversities remains unknown. In this study, we examined the cross virus neutralization of FIV genotypes A through E by sera from cats infected with a single genotype. The results indicated some relationships between phylogenetic genotype and neutralization serotype, and that cross-clade virus neutralization is possible. For example, serum from a cat infected with genotype E virus neutralized all five FIV genotypes. Our results suggest that the FIV subtyping according to the sequence diversity is partially reflected by antigenic diversity and serum neutralization.

Animals↗

PubMed1998

Construction of a recombinant feline herpesvirus type 1 expressing Gag precursor protein of feline immunodeficiency virus.

We constructed a deletion mutant of feline herpesvirus type 1 (FHV-1) and a recombinant FHV-1. The deletion mutant is the virus with a region (367 bp) deleted from the start codon of thymidine kinase (TK) gene to the SmaI site within the TK gene, and the other is a recombinant FHV-1 expressing Gag protein of feline immunodeficiency virus (FIV), in which a cDNA encoding the Gag protein of FIV was inserted at the TK deletion site of the former deletion mutant. These viruses were designated as C7301ddlTK and C7301ddlTK-gag, respectively. Growth kinetics of these viruses in Crandell feline kidney cells was similar to that of the parent C7301 strain. By immunoblot analysis, C7301 ddlTK-gag was confirmed to express the FIV Gag precursor protein in the cells.

Alphaherpesvirinae↗

PubMed1998

Cats are protected against feline immunodeficiency virus infection following vaccination with a homologous AP-1 binding site-deleted mutant.

Following establishment, via the vaginal route, of infection with an AP-1 binding-site deleted mutant (delta AP-1) of feline immunodeficiency virus (FIV), cats were challenged with a homologous intact strain (TM2) of FIV. The cats were observed for 23 weeks to evaluate the efficacy of the delta AP-1 against the homologous TM2 strain challenge. These two viruses were differentiated by Southern blotting after amplification of proviral DNA by semi-nested polymerase chain reaction in DNAs of peripheral blood mononuclear cells and tissues. A TM2-specific band was detected in one cat exposed to but not infected with delta AP-1, but not in two delta AP-1-infected. These results indicate that delta AP-1 could protect against subsequent challenge with homologous FIV TM2 strain.

Animals↗

PubMed1998

Bradykinin stimulates type II alveolar cells to release neutrophil and monocyte chemotactic activity and inflammatory cytokines.

In the present study, we evaluated the potential of bradykinin (BK) to induce the release of neutrophil and monocyte chemotactic activity (NCA and MCA) and cytokines from an alveolar type II epithelial cell line, A549 cells. BK stimulated A549 cells to release NCA and MCA in a dose- and time-dependent manner (P < 0.001). Checkerboard analysis revealed that both NCA and MCA involved chemotactic and chemokinetic activity. Molecular sieve column chromatography showed three molecular weight masses (near 19 kd, 8 kd, and 400 d) for NCA and several molecular weight peaks (near 66 kd, 25 kd, 19 kd, 16 kd, and 400 d) for MCA. The release of NCA and MCA was inhibited by cycloheximide and lipoxygenase inhibitors (P < 0.01). The NCA and MCA were inhibited by leukotriene B4 (LTB4) receptor antagonist (P < 0.01), and the concentration of LTB4 was high enough for NCA and MCA. Antibodies to interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF) attenuated NCA (P < 0.01), and antibodies to monocyte chemotactic protein-1 (MCP-1), G-CSF, and transforming growth factor (TGF)-beta attenuated MCA (P < 0.01). The levels of IL-8, G-CSF, MCP-1, and TGF-beta increased time dependently (P < 0.01). BK also stimulated the release of ILeukin-6 from A549 cells (P < 0.001). The receptors responsible for the release of NCA, MCA, and individual chemokines involved both BKB1 and BKB2 receptors. These data suggest that BK may stimulate alveolar type II pneumocytes to release inflammatory cytokines, which then may modulate the lung inflammation.

Antibodies↗

PubMed1998

Smoke extract stimulates lung epithelial cells to release neutrophil and monocyte chemotactic activity.

Inflammatory cells accumulate within the lungs of cigarette smokers. Current concepts suggest that these cells can induce protease-antiprotease and/or oxidant-antioxidant imbalance(s), which may damage the normal lung alveolar and interstitial structures. Because type II pneumocytes line the alveolar space, and because the inflammatory cells migrate and reside at the alveolus, we postulated that the type II pneumocytes might release chemotactic activity for neutrophils and monocytes in response to smoke extract. To test this hypothesis, A549 cells were cultured and the supernatant fluids were evaluated for the neutrophil and monocyte chemotactic activity (NCA and MCA) by a blind-well chamber technique. A549 cells released NCA and MCA in response to smoke extract in a dose- and time-dependent manner (P < 0.05). Checkerboard analysis showed that the activity was chemotactic. Partial characterization of NCA and MCA revealed that the activity was partly heat labile, trypsin sensitive, and ethyl acetate extractable. Lipoxygenase inhibitors and cycloheximide inhibited the release of NCA and MCA. Molecular sieve column chromatography showed multiple peaks for both NCA and MCA. NCA was inhibited by anti-human-interleukin (IL)-8 antibody, granulocyte colony-stimulating factor (G-CSF) antibody, or leukotriene (LT)B4 receptor antagonist. Monocyte chemoattractant protein (MCP)-1 antibody or LTB4 receptor antagonist inhibited MCA. Immunoreactive IL-8, G-CSF, MCP-1, and LTB4 significantly increased in the supernatant fluids in response to smoke extract. These data suggest that the type II pneumocytes may release NCA and MCA and modulate the inflammatory cell recruitment into the lung.

Antibodies↗

PubMed1998

A combined surgical and endovascular treatment for a case with five vertebro-basilar aneurysms and bilateral internal carotid artery occlusions.

BACKGROUND: Whereas multiple aneurysms may be found in 20% of patients in whom one aneurysm is discovered, the identification of five vertebrobasilar aneurysms is distinctly rare. We described such a case treated by surgical and endovascular method. CASE DESCRIPTION: A case of multiple aneurysms treated with combined surgical clipping and intravascular surgery is described. Five separate posterior circulation aneurysms and bilateral internal carotid artery occlusion were identified in one patient. Three of the aneurysms were treated surgically. Access to the fourth aneurysm was deemed difficult because of its location and because of the previously placed surgical clips; this aneurysm was treated by endovascular approaches that provided optimum therapy in this unusual multiple aneurysms case. CONCLUSIONS: We have described an unusual case of multiple posterior circulation aneurysms in the setting of bilateral internal carotid occlusions, treated by a combination of surgical and endovascular therapies. We will be able to provide safer treatment for such difficult cases in the future.

Adult↗

PubMed1998

Detection of chimaeric transcripts of the immunoglobulin heavy chain and BCL6 genes by reverse-transcriptase polymerase chain reaction in B-cell non-Hodgkin's lymphomas.

T(3;14)(q27;q32) is frequently detected in B-cell non-Hodgkin's lymphomas, especially the diffuse large cell type and the follicular type. The BCL6 gene encoding a putative transcriptional factor which resides on 3q27 rearranges to the immunoglobulin heavy chain (IgH) gene on 14q32 in this chromosomal translocation. The upstream regulatory region of the BCL6 gene is replaced by the IgH gene. Deregulation of the BCL6 gene may contribute to tumourigenesis of these diseases. The rearrangement between the IgH and BCL6 genes generates chimaeric transcripts in which the joining (J) region of the IgH gene fuses to exon 3 of the BCL6 gene. We established a method to detect these chimaeric transcripts by reverse transcriptase polymerase chain reaction (RT-PCR) using the consensus sequence of the J region and the sequence of exon 3 of the BCL6 gene as primers. Using the semi-nested RT-PCR method and a cell line carrying t(3;14)(q27;q32), we detected one lymphoma cell among 10,000 background cells. We detected these chimaeric transcripts in two out of 13 clinical samples by this method. This method can detect t(3;14)(q27;q32) easily, whereas this alteration is frequently overlooked by routine karyotype analysis. Since this technique is sensitive enough to detect a small number of lymphoma cells with this genetic abnormality, it could be employed to detect contaminating lymphoma cells in bone marrow and peripheral blood and minimal residual diseases.

Base Sequence↗

PubMed1998

Molecular cloning and sequencing of feline stromal cell-derived factor-1 alpha and beta.

The stromal cell-derived factor-1 alpha and beta (SDF-1 alpha/beta) are the ligands of fusin/CXCR4, the co-receptors of human immunodeficiency virus type 1 and the feline immunodeficiency virus. We cloned the cDNA of feline SDF-1 alpha/beta. The open reading frames of feline SDF-1 alpha/beta were 267/279 base pairs and encoded 89/93 amino acid residues.

Amino Acid Sequence↗

PubMed1998

P300 in response to the subject's own face.

The P300 event-related potentials in response to self-relevant stimuli has been reported to be different from those to non-target stimuli under a passive attention condition. In the present study the P300 in response to the subject's own face was examined. Twelve right-handed volunteers served as subjects. In two separate conditions, deviant (subject's own face and red square; 30%), non-target (two unfamiliar faces; 30% each), and target (famous face; 10%) stimuli were randomly presented on a computer screen. P300 amplitudes in response to the red square were larger than those to the unfamiliar faces, but were significantly lower than those to the subject's own face. The subject's own face in normal population may have an intense relevance to the subjects which has an additional effect over the simple orienting response.

Adult↗

PubMed1998

Delayed cyst formation after radiosurgery for cerebral arteriovenous malformation: two case reports.

Two patients who underwent gamma knife radiosurgery for ruptured cerebral arteriovenous malformations (AVM) developed cystic lesions at 78 and 111 months after undergoing treatment. Both patients presented initially with intracerebral hemorrhage. In one patient, the cystic lesion was discovered during routine follow-up imaging and clinical examination revealed homonymous hemianopsia; the second patient presented with seizure and the lesion was identified more than 9 years after radiosurgery. One patient underwent resection of the nidus and histologic analysis of the resected specimen showed vessels in various stages of obliteration. The present paper discusses the possible mechanism for the delayed development of cystic lesions, and the possibility that radiation-induced vascular changes may continue in a nidus even when angiography shows complete obliteration of the nidus.

Adult↗