Biomedical subjects

T Uede

Publications and source records attributed to T Uede.

At least 109 records · Page 6Linked to original sources

PubMed1995

[Magnetic resonance imaging of supratentorial and parafalcial empyema].

The authors report the MR imaging of two patients with multiple subdural empyemas, including one in the interhemispheric fissure. MRI demonstrated convexity and interhemispheric collections which were mild hyperintense relative to CSF, hypointense relative to gray and white matter on T1W1, and marked hyperintense relative to CSF, and brain on T2W1. On the basis of signal intensity differences, MRI can distinguish subdural empyemas from most sterile effusions and chronic subdural hematomas with similar CT appearances. MRI was found to be clearly more sensitive to subdural empyemas than CT, though such lesions missed on CT were considered to be relevant. MR was superior to CT in demonstrating the nature, presence, and extent of these lesions. In both cases, the capsule of the lesions demonstrated enhancement, and connection between each lesion was obvious on contrast-enhanced MRI. It seems that contrast-enhanced MR image may detect encapsulation of an abscess which can not be detected from contrast-enhanced CT. We emphasized that the most significant factor in the successful surgical management of multiple subdural empyema, particularly including interhemispheric collections is the accurate location of pus. This can be reliably achieved with MR imaging.

Adolescent↗

PubMed1995

[The molecular mechanism of costimulatory signal for T cell activation].

The initiation of T cell responses against antigens requires two distinct signals. The first, the essential signal is the engagement of T cell receptor to antigen peptide in the context of MHC molecules on antigen presenting cells (APC). The presence of the second signal (costimulatory signal) determines whether responding T cells to be fully responsive or to be anergic (antigen specific nonresponsiveness). There are numbers of such costimulatory receptor/ligand pairs including B7/CD28: CTLA4, VCAM-1/VLA4, ICAM-1/LFA-1, HSA/unknown, and LFA-3/CD2. Among those ligand receptor pairs, B7/CD28 pathway is chosen and the molecular mechanism how T cell responses are regulated by B7/CD28 is discussed.

Animals↗

PubMed1994

Identification of an alternatively spliced form of the murine homologue of B7.

B7 on antigen presenting cells is a costimulatory ligand necessary for full activation of T cell. Receptors for B7 have been known as CD28 or CTLA4. We here show that in addition to B7 mRNA, an alternatively spliced mRNA (designated as MB7-2 mRNA), that immunoglobulin (Ig)C-like domain coded by exon 3 has been spliced out, is found in activated murine splenic B cells by reverse transcriptase-polymerase chain reaction analysis. Chinese hamster ovary (CHO) cells transfected with MB7-2 bound CTLA4Ig less well than those expressing B7, but bound CD28Ig to a similar extent, indicating that IgV-like domain contains the complete binding site for CD28. In addition, IgC-like domain may participate in an increase in the affinity for CTLA4. Thus, MB7-2 represents a new form of the murine B7 with different receptor binding properties.

Alternative Splicing↗

PubMed1994

Expression of adhesion molecules on human hematopoietic progenitor cells at different maturational stages.

In this report we examined the expression of several adhesion molecules on human hematopoietic progenitor cells at different maturational stages. Human hematopoietic progenitor cell-enriched fractions were prepared from bone marrow cells by depleting lymphocytes and monocytes (CD2+, CD14+ and CD19+ cells). These cells were separated into adhesion molecule-positive and -negative cell populations by immunomagnetic separation methods and then assessed for their ability to form various colony forming cells (CFC). CD44 and CD49d were expressed on multipotent hematopoietic progenitor cells, or mixed colony forming units (CFU-Mix), erythroid burst forming units (BFU-E), granulocyte-macrophage CFU (CFU-GM) and erythroid CFU (CFU-E). Leu8 was expressed on CFU-Mix, BFU-E and some populations of CFU-GM, but not CFU-E. CD11a was expressed on some populations of CFU-Mix, CFU-GM and BFU-E. CD54 was expressed only on some populations of CFU-GM. These results suggest that Leu8, CD44, CD49d and CD11a appear to play important roles in the differentiation and proliferation of human hematopoietic progenitor cells at different maturational stages in the bone marrow microenvironment.

Antigens, CD↗

PubMed1994

Demonstration of the interaction between the CD23 molecule and the galactose residue of glycoproteins.

The CD23 molecule is a low-affinity receptor for IgE and has a marked homology in amino acid sequence with C-type animal lectins, including asialoglycoprotein receptor. We tested whether the CD23 antigen can indeed interact with the sugar chain of glycoproteins. Detergent extract of the membrane component from Epstein-Barr Virus (EBV)-transformed human B-cell line, L-KT9 cells, was incubated with asialofetuin (ASF)-coupled Sepharose, and bound proteins were effectively eluted by 0.3 M lactose or galactose which were among the competitive sugars tested. In this eluate, the CD23 molecule was detected by an immunoblotting technique. Because fetuin has both an N- and O-type sugar chain on the molecule, we tested which type of sugar chain can interact with CD23. The CD23 molecule interacted with asialocasein having a sugar chain with the Gal-GalNAc structure with asialobovine submaxillary mucin having the GalNAc structure, and also with ASF; however, it faintly interacted with ASF after removal of the O-type sugar chain by beta-elimination. These results showed that the CD23 molecule can, indeed, interact with the galactose residue, especially with the Gal-GalNAc rather than the Gal-GlcNAc structure of the terminal sugar chain of glycoproteins.

Acetylgalactosamine↗

PubMed1994

Integrin expression and ability to adhere to extracellular matrix proteins and endothelial cells in human lung cancer lines.

We examined the integrin expression in 19 human lung cancer cell lines with monoclonal antibodies to the integrin subunits alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, alpha 6, beta 1, beta 2, and beta 4. We measured their ability to adhere to the extracellular matrix (ECM) and human umbilical vein endothelial cells (HUVECs). Almost all lines expressed the beta 1 subunit and approximately half of the lines expressed the beta 4 subunit; by contrast, none expressed the beta 2 subunit. Subunits alpha 2, alpha 3, alpha 5 and alpha 6 were frequently expressed, whereas very few lines expressed alpha 1 and alpha 4. Most lines adhered strongly to ECM (type I collagen, laminin and fibronectin) in correspondence to their expression of integrins. Binding by most lines to fibronectin was completely inhibited by arginine-glycine-aspartic acid (RGD) peptide. Three lines that expressed few or no integrins had very weak ability to adhere to ECM. Strong binding to HUVECs was found in most lines, but the three lines had very little ability to adhere to HUVECs. Binding to HUVECs was strongly inhibited at 4 degrees C, under divalent cation-free conditions and by antibodies to the beta 1 subunit. These results suggest that lung cancer cells adhere to ECM and endothelial cells through integrins, especially the beta 1 subfamily.

Amino Acid Sequence↗

PubMed1994

1C5 antigen: cancer-associated protein expressed by cervical adenocarcinomas and beta-casein.

The monoclonal antibody 1C5 reacts with an antigenic determinant present in 90% of the cases of adenocarcinoma of the uterine cervix. The antigen defined by the 1C5 antibody exhibits immunological characteristics similar to those of skim milk (bovine buttermilk). 1C5-defined antigen obtained from tumor extract and skim milk binds specifically to wheat germ agglutinin (WGA) lectin. The 1C5-defined antigenic activity of a WGA lectin-bound fraction was eluted at 0.7-0.8 M NaCl off a Mono Q column. Use of an inhibition assay and a dot immunobinding assay revealed that the antigenic epitope defined by the 1C5 MoAb from skim milk exists within the first 28 amino acids of the beta-casein peptide.

Adenocarcinoma↗

PubMed1994

In vivo cytokine gene expression in various T cell subsets of the autoimmune MRL/Mp-lpr/lpr mouse.

We have used the reverse transcriptase polymerase chain reaction (RT-PCR) technique to assess the expression of cytokine genes in various T cell subsets of autoimmune-prone mice. Our study confirmed the previously described features in lpr mice that IFN-gamma, TNF-alpha, and TNF-beta were transcribed by various T cell subsets. We in this study demonstrated that double negative (DN) T cells, the major cell population in lpr mice, failed to express interleukin-3 (IL-3), IL-4, IL-5, and IL-6 genes that influence B cell growth and activation. In contrast, DN T cells expressed Eta-1 gene that is shown to augment polyclonal activation of B cells and immunoglobulin production. Thus, it is conceivable that T cell-derived B cell-stimulatory activities in MRL/lpr mice can be attributed to Eta-1, rather than IL-3, IL-4, IL-5 or IL-6. We also demonstrated that CD4+ T cells infiltrating into kidney tissues of MRL/lpr mice expressed various cytokine genes such as IL-1, IL-5, IL-6, IFN-gamma, TNF-alpha, TNF-beta and TGF-beta.

Animals↗

PubMed1994

[Superacute changes in blood-brain barrier following cerebral venous hypertension due to an embolic occlusion of cerebral venous sinus].

Pathophysiological mechanism of hemorrhagic infarction and brain edema following obliteration of venous outflow tract has been poorly understood. We analyzed a superacute change of the blood-brain barrier in a rat experimental model of venous hypertension produced by an embolic occlusion of superior sagittal sinus (SSS). In all thirty-seven animals received retrograde embolization, marked increments of SSS pressure were noted immediately after embolic occlusion of the sinus. Severity and geographical patterns of the disruption of blood-brain barrier were then analyzed photomicrographically, visualized by the autofluorescence of the exuded Evans blue with Hematoxylin-eosin stain. Relationship between the degree of SSS pressure increment and the severity of the blood-brain barrier destruction was studied. In ten out of the seventeen animals (59%), analyzed five minutes after embolization, exudation of the dye was demonstrated. The degree of SSS pressure increment in the animals with dye exudation was higher than in the animals without them. In five out of the nine animals (56%), analyzed fifteen minutes after embolization, exudation of the dye was also demonstrated. The degree of SSS pressure increments in the animals with dye exudation was statistically higher than those in the non-exuded ones. Especially, all the animals with SSS pressure higher than 75 mmHg were associated with severe exudation of the dye. The exudation of the dye was more prominent in the white matter than in the cortical gray matter. Following pathological analysis have revealed that exudation of the dye was most prominent around the capillary and the venule in the white matter. Microvacuolation around these vessels was also noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1994

[A case of an intracerebral mass lesion consisting of traumatic granulation tissue].

We reported a rare case of an intracerebral granulomatous lesion accompanying severe edema formation in the healing stage of traumatic brain contusions. A 44-year-old male patient came to our outpatient clinic due to progressing headache and nausea. Upon computed tomographic examination, a low density mass with strong surrounding edema was detected at the right frontal base. Magnetic resonance images revealed a high intensity mass on both T1- and T2-weighted images at the right frontal base. Upon intravenous injection of a contrast agent, this lesion exhibited multifocal marginal contrast enhancement. Two additional small enhanced mass lesions were detected at the tip of the right temporal lobe and the medial portion of the left temporal lobe. We tentatively diagnosed it as a right frontal brain tumor and attempted the total removal of the right frontal mass. Unexpectedly, pathological diagnosis was intracerebral granulation tissue associated with accumulation of hemosiderin-laden macrophages and capillary wall thickening. In addition, there was no reactive gliosis. We speculated on the pathogenesis of intracerebral granulation tissue as follows. Since the patient was a heavy drinker and often fell down when he was drunk, it is likely that he might be suffering from intracerebral hematomas due to traumatic contusions. This assumption may be supported by the fact that an old subdural hematoma was observed during the operation and the radiological examination revealed multiple lesions. The gathering and proliferation of mesenchymal cells possibly derived from blood circulation probably began at the site of the damaged brain tissue, thus forming intracerebral granulation tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[A case of suprasellar intradural chordoma].

An extraosseous and intradural chordoma of the suprasellar region is described in a 54-year-old male who presented himself with left homonymous hemianopia. Computed tomography showed an isodensity tumor containing a cyst in the suprasellar region. Magnetic resonance images demonstrated the tumor as an isointense mass with heterogeneous enhancement after intravenous administration of a contrast agent, and as a high signal intensity mass on T2-weighted images. The associated cyst was also clearly demonstrated. The tumor was diagnosed preoperatively as a craniopharyngioma and was resected using the frontobasal interhemispheric approach. However, the resected tumor had the typical histological and immunohistochemical characteristics of chordoma. Only ten cases of totally extraosseous and intradural chordoma have been reported. The histogenetic background of this tumor is also discussed in this paper.

Brain Neoplasms↗

PubMed1994

[Technical tactics to preserve cortical venous drainage in interhemispheric approach for anterior communicating artery aneurysms].

The interhemispheric approach has been selected for clipping of the anterior communicating artery aneurysm located high above the sphenoidal plate, and in a posterior direction. However, this approach is sometimes complicated with postoperative hemorrhagic infarction due to excess brain retraction combined with damages of the cortical bridging veins. We have devised a modification in this approach to eliminate these complications. Our newly devised methods include the following; 1) Small bifrontal craniotomy performed, 2) Continuous ventricular drainage performed to minimize the effect of compression by the spatula during resection of interhemispheric fissure, 3) Bifrontal dural incision made along the frontal skull base, 4) Mobilization of the major cortical vein in the operated field, if necessary, by resection of the overlying arachnoid membrane with or without sacrificing its small tributaries, 5) Gradual dissection of the olfactory nerves according to the process of operation. We analysed the incidence of operative complications in thirteen consecutive cases with this approach. Major frontal ascending veins were carefully preserved in all cases. None showed hemorrhagic infarction, regardless of the cortical venous drainage patterns. The degree of smell preserved in 10% of the examined 11 cases was more than unilateral. In conclusion, this method is useful for the elimination of perioperative complications even in the acute stage of subarachnoid hemorrhage.

Adult↗

PubMed1993

Transcriptional repression and differential splicing of Fas mRNA by early transposon (ETn) insertion in autoimmune lpr mice.

Lpr (lymphoproliferation) is a recessive trait caused by a mutation in the Fas gene which reduces the Fas transcript substantially. When reverse transcription polymerase chain reaction (RT-PCR) was performed using pairs of primers surrounding a particular portion of Fas mRNA, wild-type and approximately 180 base pair (bp) longer PCR products were consistently generated from lpr thymocytes. The latter contained an insertion of 183 nucleotides which was 98.9% homologous to early transposon (ETn) which was found in an immunoglobulin switch region of murine plasmacytoma, P3.26Bu4. These data clearly indicate that ETn insertion into the Fas gene intron causes transcriptional repression. However, this defect may be leaky due to the production of intact Fas mRNA by splicing out ETn-containing intron from primary Fas transcripts. The inserted 183 bp fragment has a potential to code in-frame 61 amino acids, so that the mutant Fas antigen may also be produced. Low level expression of wild-type and mutant Fas antigens may be relevant to the variable phenotype in lpr mice.

Amino Acid Sequence↗

PubMed1993

Distribution of integrins and their matrix ligands in osteogenic sarcomas.

We studied the expression of the members of the beta 1 integrin family and extracellular matrix ligands in osteosarcoma tissues. Immunostaining of primary osteosarcomas with use of specific antibodies for alpha 1-alpha 6 integrin subunits, fibronectin, type-I collagen, and laminin gave characteristic patterns: despite the diffuse expression of type-I collagen in all 16 osteosarcomas, collagen receptors were detected in only one. Laminin and laminin receptors were expressed poorly. In contrast, the alpha 4 and alpha 5 fibronectin receptors were found in 100 and 75%, respectively, which correlates very well with the strong expression of fibronectin in the stroma. The other ligand for alpha 4, vascular cell adhesion molecule-1, was not expressed in the seven specimens tested. Therefore, primary osteosarcomas closely interact with fibronectin through alpha 4 and possibly alpha 5 subunits of the beta 1 integrin. We also examined the expression of integrins in six metastatic foci in five patients. Some change for the expression was detected in all six specimens, however, the change varied. In contrast, osteosarcoma cells obtained from invasive portions of tumors exhibited new and augmented expression of certain integrins in two of the three cases in which their ligands were also expressed.

Adolescent↗

PubMed1993

Spontaneous and antibody directed cytotoxicity of double-negative T cells from autoimmune mice.

MRL/Mp-lpr/lpr (MRL/lpr) mice develop a syndrome similar to systemic lupus erythematosus in humans. This strain of mice is characterized by the progressive accumulation of CD4-CD8- (double-negative; DN) T cells which express increased levels of cell adhesion molecules such as CD44 and heat stable antigen (HSA). The DN T cells exhibited a higher level of spontaneous cytolytic activity and contained a higher level of serine esterase as compared with T cells of MRL/Mp-+/+ (MRL/+) mice. We also found that mAbs against CD44, Mel-14, CD45R, and HSA could augment the cytolytic activity of DN T cells of MRL/lpr mice. Antibody-mediated augmentation of cytolytic activity of DN T cells was due to conjugate formation in which the Fc portion of mAb bound to the Fc gamma receptor on target cells and the Fab portion of mAb bound to corresponding cell surface antigens on DN T cells. The antibody-mediated augmentation of cytolytic activity was not detected in T cells of MRL/+ mice and lymphokine activated killer (LAK) cells of C57BL/6 mice. In contrast, anti-CD3 mAbs could augment the cytolytic activity of DN T cells, T cells as well as LAK cells. mAbs against LFA-1 and VLA-4 failed to augment the cytolytic activity of three different effector cells. It should be noted that anti-CD3 mAb-mediated cytolytic activity of DN T cells was substantially reduced by anti-LFA-1 mAb. However, CD44, Mel-14, CD45R as well as HSA-mediated cytolytic activity of DN T cells was not inhibited by anti-LFA-1 mAb.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Functional and phenotypical analysis of subsets of rat CD4+ T cells.

Rat CD4+ T cells were divided into two distinct subsets by a monoclonal antibody RTH-1 recognizing a unique epitope on rat CD45R. Cellular distribution of OX-22- and RTH-1-defined antigens was the same. However, OX-22 and RTH-1 recognized different epitopes that exist on rat CD45R. The expression of IL-4 gene was detected only in RTH-1low CD4+ T cell subset upon various stimulations. In contrast, the expression of IL-2 and IFN-gamma gene varied depending upon the nature of stimuli. The increased cell surface expression of CD44 was detected in RTH-1high CD4+ T cell subset. Conversely the increased expression of CD2 was detected in RTH-1low CD4+ T cell subset. The expression of CD3 and LFA-1 was not significantly different between RTH-1high and RTH-1low subsets.

Animals↗

PubMed1993

Functional analysis of mononuclear cells infiltrating into tumors: establishment of T cell hybridomas exhibiting distinct interacting abilities with endothelial cells and extracellular matrix components.

We have established eleven T cell hybridoma cell lines to investigate mechanisms controlling interaction of T lymphocytes with endothelial cells as well as extracellular matrix (ECM) proteins at the clonal level. T cell hybridomas were characterized and subdivided into four groups on the basis of their interaction behavior with high endothelial venules (HEV). Group 1 (G1) exhibited strong adhesiveness. The binding was temperature- and divalent cation-dependent. Group 2 exhibited both adhesiveness and transendothelial migration (TEM, i.e., transmigration beneath the cytoplasm of endothelial cells). Group 3 exhibited strong TEM. G2 and G3 hybridomas exhibited temperature-independent and divalent cation-independent binding to HEV. Group 4 exhibited nonspecific adhesiveness to the surface of a slide glass. BW 5147, a parent of T cell hybridomas, was classified as G4. TEM was dependent on both the nature of T cell hybridomas and endothelial cells. TEM was completely temperature-dependent. TEM of G3 hybridomas was not divalent cation-dependent. Each group of T cell hybridomas interacted with various ECM components.

Amino Acid Sequence↗

PubMed1993

Effect of local administration of lymphokine-activated killer cells and interleukin-2 on malignant brain tumor patients.

Nine patients with malignant brain tumors were treated with intratumoral infusion of lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2). LAK cells were generated from macrophage-depleted peripheral blood lymphocytes by culturing with IL-2 for 4 days. The resulting LAK cells showed strong cytotoxic activity against tumor target cells. Three patients received sufficient LAK cells (> or = 5.76 x 10(8)) to show partial tumor response by computed tomography and clinical signs. No severe neurological side effects occurred in any patient. Intratumoral administration of LAK cells and IL-2 can be effective in patients with malignant brain tumors.

Adult↗