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Biomedical subjects

T Oda

Publications and source records attributed to T Oda.

At least 199 records · Page 11Linked to original sources
PubMed1997

Interactions of CBL with BCR-ABL and CRKL in BCR-ABL-transformed myeloid cells.

The Philadelphia chromosome, detected in virtually all cases of chronic myelogenous leukemia (CML), is formed by a reciprocal translocation between chromosomes 9 and 22 that fuses BCR-encoded sequences upstream of exon 2 of c-ABL. The BCR-ABL fusion creates a gene whose protein product, p210BCR-ABL, has been implicated as the cause of the disease. Although ABL kinase activity has been shown to be required for the transforming abilities of BCR-ABL and numerous substrates of the BCR-ABL tyrosine kinase have been identified, the requirement of most of these substrates for the transforming function of BCR-ABL is unknown. In this study we mapped a direct binding site of the c-CBL proto-oncogene to the SH2 domain of BCR-ABL. This interaction only occurs under conditions where c-CBL is tyrosine-phosphorylated. Despite the direct interaction of c-CBL with the SH2 domain of BCR-ABL, deletion of the SH2 domain of BCR-ABL did not result in an alteration in the complex formation of BCR-ABL and c-CBL, suggesting that another site of direct interaction between c-CBL and BCR-ABL exists or that another protein mediates an indirect interaction of c-CBL and BCR-ABL. Since CRKL, an SH2, SH3 domain-containing adapter protein is known to bind directly to BCR-ABL and also binds to tyrosine-phosphorylated c-CBL, the ability of CRKL to mediate a complex between c-CBL and BCR-ABL was examined.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Glial tau-positive structures lack the sequence encoded by exon 3 of the tau protein gene.

Tau protein comprises six distinct isoforms defined by the presence or absence of sequences encoded by alternatively spliced exon 2, 3 and 10. We have investigated immunohistochemically the expression of exon 3-derived fragment (E-3) of tau protein in brains of patients with Alzheimer's disease (AD) and other neurodegenerative diseases in which the abnormal accumulation of tau protein takes place. In AD, a subset of neurofibrillary tangles, neuropil threads and dystrophic neurites in senile plaques were stained positively with an anti-E-3 antibody. In sharp contrast, glial tau-positive structures, such as astrocytic plaques and oligodendroglial coiled bodies, were negative for E-3 in all cases examined in this study. This is the first report to discriminate tau-positive inclusions in glial cells from those in neurons at the molecular level.

Aged↗
PubMed1997

Direct binding of CRKL to BCR-ABL is not required for BCR-ABL transformation.

CRKL has previously been shown to be a major tyrosine phosphorylated protein in neutrophils of patients with BCR-ABL+ chronic myelogenous leukemia and in cell lines expressing BCR-ABL CRKL and BCR-ABL form a complex as demonstrated by coimmunoprecipitation and are capable of a direct interaction in a yeast two-hybrid assay. We have mapped the site of interaction of CRKL and BCR-ABL to the amino terminal SH3 domain of CRKL with a proline rich region in the C-terminus of ABL. The proline-rich region was mutated and the effect of this deletion on BCR-ABL transforming function was assayed. Our data show that this deletion does not impair the ability of BCR-ABL to render myeloid cells factor independent for growth. In cells expressing the proline deletion mutation of BCR-ABL, CRKL is still tyrosine phosphorylated and forms a complex with BCR-ABL as demonstrated by coimmunoprecipitation. Our data suggest that the interaction between CRKL and the proline deletion mutant of BCR-ABL is an indirect interaction as CRKL does not interact directly with the proline deletion mutant of BCR-ABL in a gel overlay assay or in a yeast two-hybrid assay. Thus, a direct interaction of CRKL and BCR-ABL is not required for CRKL to become tyrosine phosphorylated by BCR-ABL and suggests that CRKL function may still be required for BCR-ABL function through an indirect interaction.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Glomerular proliferating cell kinetics in acute post-streptococcal glomerulonephritis (APSGN).

To investigate the time sequence of glomerular cell proliferation in acute human glomerulonephritis, renal biopsy tissues were examined from 15 acute post-streptococcal glomerulonephritis (APSGN) patients (who were biopsied 1-31 days after onset), using an immunoperoxidase technique with monoclonal antibodies against proliferating cell nuclear antigen (PCNA) and various cell surface markers. Few, if any, PCNA+ cells were observed in normal glomeruli, but many cells were positive for PCNA in the acute phase of APSGN. Glomerular PCNA+ cells were observed either within glomerular tufts, or lining Bowman's capsule (parietal epithelial cells); the number of positive cells tended to decrease exponentially as the disease duration increased (r = -0.91, P < 0.0001). PCNA+ cells within glomerular tufts were further identified by double immunostaining. PCNA was not found in PMN or T cells, but a small proportion of macrophages were PCNA+. Most of the remaining PCNA+ cells were resident glomerular cells; the proportion of PCNA+ endothelial cells (CD31+) was over 80 per cent in the early phase, but as the disease continued the proportion of mesangial cells (alpha-smooth muscle actin+) increased to about half of the total PCNA+ cells within the tuft. These data indicate that the hypercellular glomeruli in APSGN are due not only to immune cell infiltration, but also to resident glomerular cell proliferation, probably induced by locally produced growth factors.

Acute Disease↗
PubMed1997

Distribution of cerebral cortical lesions in corticobasal degeneration: a clinicopathological study of five autopsy cases in Japan.

We investigated five Japanese patients with autopsy-proven corticobasal degeneration (CBD) both clinically and pathologically, and examined the distribution of their cerebral cortical lesions in hemisphere specimens. The lesions were classified into three categories (slight, moderate and severe). Only two of our patients had clinical features considered to be typical of CBD. Severe lesions were present in the posterior portions of the frontal lobe, anterior to the precentral gyrus in two patients with the clinical diagnosis of CBD. By comparison, in two patients with clinically diagnosed frontal Pick's disease, and one with the clinical diagnosis of progressive supranuclear palsy (PSP), severe lesions were seen in the anterior portions of the frontal lobe. The primary motor area of all five had mostly slight to moderate lesions. We postulate that the clinical features of CBD have a much wider spectrum than previously believed. Our data also indicate that the lesion responsible for limb-kinetic apraxia in CBD is in the premotor cortex. We suggest that when the anterior portions of the frontal lobe are damaged, the clinical picture mimics those of Pick's disease and PSP. In addition, we consider that focal cerebral atrophy of CBD is multicentric.

Aged↗
PubMed1997

Involvement of neutrophil elastase in crescentic glomerulonephritis.

To elucidate the role of neutrophils in the tissue damage of crescentic glomerulonephritis (GN), we examined neutrophils infiltrated in renal tissues and the localization of neutrophil elastase (NE), as a neutrophil-derived tissue destructive mediator, using an immunohistochemical technique with antibodies specific for neutrophils and neutrophil elastase; the enzyme histochemical technique (chloroesterase staining) also was used to detect neutrophils. In normal controls, neutrophil infiltration was scarce, and NE was localized in neutrophil cytoplasm. Neutrophils were abundant in crescentic GN and infiltrated in the glomerulus and interstitium; the infiltrating neutrophils were often aggregated. NE was localized in the cytoplasm of neutrophils and also appeared extracellularly (in granular or diffuse patterns) in glomerular necrotizing lesions, crescents, ruptured portions of Bowman's capsules, and in periglomerular and perivascular sites of the interstitium. Moreover, urinary concentration of NE measured by enzyme-linked immunosorbent assay (ELISA) in crescentic GN patients was significantly higher than in normals (93.6 +/- 13.3 v 1.4 +/- 0.5 microg/g x Cr, respectively; P < .001). These data suggest that NE plays a significant role in renal tissue damage, especially in the formation of glomerular necrotizing and crescentic lesions and in periglomerular interstitial lesions of crescentic GN.

Antigens, CD↗
PubMed1997

Recovery of the systolic time intervals by coenzyme Q10 in patients with a load-induced cardiac dysfunction.

In patients with a load-induced cardiac dysfunction (LCD), the left ventricular (LV) stroke work is supernormal at rest, but then becomes subnormal during handgrip (HG). The LCD usually occurs in children with the mitral valve prolapse (MVP). Our catheterization study revealed that the end-diastolic pressure (EDP) of both ventricles was elevated in LCD patients. In this study, the LV and right ventricular (RV) systolic time (ET) were measured by echocardiograms. The mitral inflow peak velocities, E and A, were also measured by the pulsed Doppler method. Subjects were divided into four groups, each consisting of 16 individuals: group 1, normal children; group 2, LCD patients; group 3, recovered children from LCD, the same individuals as group 2, but after coenzyme Q10 (CoQ) therapy; and group 4, asymptomatic children with MVP. In group 2, the mean PEP and PEP/ET were significantly smaller and the peak A velocity was significantly larger than in groups 1, 3 and 4. Among groups 1, 3 and 4, no intergroup differences were found regarding the PEP/ET and A. In LCD patients, a depressed inotropic state of the myocardium may result in a high EDP due to the Frank-Starling mechanism, and such a high EDP may then cause STI changes and a large A velocity. CoQ may also return abnormal STIs in LCD patients to normal, probably by improving the inotropic state and, as a consequence, reducing the high EDP of the LV and RV to a normal level.

Adolescent↗
PubMed1997

Variable deposition of amyloid beta-protein (A beta) with the carboxy-terminus that ends at residue valine40 (A beta 40) in the cerebral cortex of patients with Alzheimer's disease: a double-labeling immunohistochemical study with antibodies specific for A beta 40 and the A beta that ends at residues alanine42/threonine43 (A beta 42).

Amyloid beta-protein (A beta) deposits in the cerebral cortices of patients with Alzheimer's disease (AD) were investigated immunohistochemically to determine their carboxy terminal sequences. Antibodies specific for A beta terminating at residue valine40 (A beta 40) and at residues alanine42/threonine43 (A beta 42) were used. Virtually all parenchymal A beta deposits were positive for A beta 42. Many of these deposits were also partially or completely labeled for A beta 40. The degree of A beta 40 labeling varied from area to area within a given brain and from AD case to AD case. In contrast to parenchymal deposits, A beta 40 labeled essentially all the vascular deposits which constitute amyloid angiopathy (AA), with A beta 42 occurring variably in some of these deposits. Occasional AA was found, however, in which A beta 42 predominated or was exclusively deposited. Such a diversity of A beta species, both in brain parenchyma and in AA, suggests that multiple C-terminal processing mechanisms occur in the cell types responsible for these deposits.

Aged↗
PubMed1997

Mutations in the human Jagged1 gene are responsible for Alagille syndrome.

Alagille syndrome (AGS) is an autosomal-dominant disorder characterized by intrahepatic cholestasis and abnormalities of heart, eye and vertebrae, as well as a characteristic facial appearance. Identification of rare AGS patients with cytogenetic deletions has allowed mapping of the gene of 20p12. We have generated a cloned contig of the critical region and used fluorescent in situ hybridization on cells from patients with submicroscopic deletions to narrow the candidate region to only 250 kb. Within this region we identified JAG1, the human homologue of rat Jagged1, which encodes a ligand for the Notch receptor. Cell-cell Jagged/Notch interactions are known to be critical for determination of cell fates in early development, making this an attractive candidate gene for a developmental disorder in humans. Determining the complete exon-intron structure of JAG1 allowed detailed mutational analysis of DNA samples from non-deletion AGS patients, revealing three frame-shift mutations, two splice donor mutations and one mutation abolishing RNA expression from the altered allele. We conclude that AGS is caused by haploinsufficiency of JAG1.

Alagille Syndrome↗
PubMed1997

Identification and characterization of two novel SH2 domain-containing proteins from a yeast two hybrid screen with the ABL tyrosine kinase.

To further our understanding of the molecular mechanism of Bcr-Abl mediated transformation, a yeast two hybrid screen was used to identify proteins binding to the Abl tyrosine kinase. Two partial cDNAs encoding novel SH2 domain-containing proteins were cloned and designated Shd and She. Both have homology to Shb, a previously reported SH2 domain-containing protein. Northern blot analysis showed that She is expressed in heart, lung, brain, and skeletal muscle, while expression of Shd is restricted to the brain. The deduced amino acid sequence of the full length mouse Shd cDNA contains an amino-terminal proline-rich region, and a carboxyterminal SH2 domain. A bacterially expressed Shd domain bound multiple tyrosine-phosphorylated proteins with relative molecular weights of 200, 170, 130, 100, 90, 78, 72 and 32 kDa from K562 cell lysates. Shd contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases. Shd was tyrosine phosphorylated in COS-7 cells co-transfected with Shd and c-Abl or Bcr-Abl. These results suggest that Shd may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Experimental acute glomerulonephritis induced in the rabbit with a specific streptococcal antigen.

FITC-labelled IgG obtained from patients convalescing from acute poststreptococcal glomerulonephritis (APSGN) stains glomeruli of patients with early APSGN. We previously reported a streptococcal antigen (preabsorbing antigen (PA-Ag)) that preabsorbed the stain out of sera from the convalescent patients and thus prevented glomerular staining. To confirm the nephritogenicity of PA-Ag, we administered up to 40 mg of this antigen to rabbits for 8 days and observed them for up to 9 weeks. Immunohistological analysis showed diffuse and global glomerular staining for C3 without notable staining for gamma-globulin. Light microscopic examinations revealed slight to moderate proliferative glomerulonephritis with exudative change. Control rabbits, which received similar doses of bovine serum albumin, did not show significant staining for C3. A transient and significant decrease in CH50 was observed from weeks 3 to 7 (9.7 +/- 0.3 U/ml at week 3; normal range 12.9 +/- 0.6 U/ml). This experimental model showed a resemblance to immunological and immunohistological features of APSGN in humans. Although the precise mechanisms are yet to be determined, complement activation by PA-Ag seems to hold a key position in this model and in the human disease.

Acute Disease↗
PubMed1997

Temperature- and pH-dependent cytotoxic effect of the hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata on various cell lines.

We investigated the cytotoxicity of CEL-III, one of four Ca2+-dependent galactose/N-acetylgalactosamine (GalNAc)-binding lectins from the marine invertebrate Cucumaria echinata. Among six cell lines tested, MDCK cells showed the highest susceptibility to CEL-III cytotoxicity and its LD50 was estimated to be 53 ng/ml, while no significant cytotoxicity of CEL-III was observed in CHO cells up to 10,000 ng/ml. In the presence of 0.1 M lactose, the cytotoxicity of CEL-III was strongly inhibited. The binding studies using FITC-labeled CEL-III revealed that the amount of CEL-III bound to MDCK cells was about 2-fold greater than that in the case of CHO cells. The cytotoxicity of CEL-III increased with decreasing temperature. The surviving fractions of Vero cells exposed to CEL-III at 4 degrees C were immediately decreased, and more than 90% of exposed cells were killed within 20 min, whereas at 37 degrees C much longer exposure period (more than 10 h) was required to kill 50% of the cells. CEL-III induced the release of carboxyfluorescein (CF) from CF-loaded MDCK cells and this activity was markedly increased at alkaline pH (pH 10) and at lower temperature (4 degrees C). Even in CHO cells, considerable CF release was induced by CEL-III at 4 degrees C and at pH 10 but not at pH 7.5 at both temperatures. In agreement with these results, CHO cells exposed to CEL-III at 4 degrees C and at pH 10 were killed in a dose-dependent manner. These results suggest that CEL-III exhibits cytotoxicity through damaging the plasma membrane by pore-formation in a temperature- and pH-dependent manner. Different susceptibility of each cell line to CEL-III cytotoxicity may be due to differences in the processes leading to pore-formation after binding to cell-surface carbohydrates.

Animals↗
PubMed1997

Functions of characteristic Cys-Gly-His-Cys (CGHC) and Gln-Glu-Asp-Leu (QEDL) motifs of microsomal ER-60 protease.

The human ER-60 protease cDNA was expressed in Escherichia coli BL21 (DE3) cells using the pET-20b(+) T7 promoter. The recombinant ER-60 protease was obtained in a water-soluble form and purified through four sequential chromatographies. The ER-60 protease contains two CGHC motifs. When an alanine residue was substituted for the N-terminal cysteine residue in both motifs, the protease activity was not lost. However, when the C-terminal cysteine residue in both motifs was replaced by a serine residue, the cysteine protease activity, which was inhibited by p-chloromercuribenzoic acid (pCMB) but not by diisopropyl fluorophosphate (DFP), changed to serine protease activity, which was inhibited by DFP but not by pCMB. These results indicate that the C-terminal cysteine residue(s) of the CGHC motifs may constitute the active site(s) of ER-60 protease. The ER-60 protease has a C-terminal QEDL sequence, which was proved to serve as an ER-retention signal by deletion of the QEDL sequence. However, because QEDL could not serve as the ER-retention signal for protein disulfide isomerase or ERp72, it is suggested that amino acid residue(s) of ER-60 protease, other than the QEDL sequence itself, is complimentarily responsible for the ER retention of this protein.

Amino Acid Sequence↗
PubMed1997

B7-1(CD80)-transfected human glioma cells and interleukin-12 directly stimulate allogeneic CD8+ T cells.

To obtain more effective cytotoxic T lymphocytes (CTLs), we examined the effect of B7 costimulation and interleukin-12 (IL-12) on the induction of allogeneic CTLs. Peripheral blood lymphocytes (PBLs) or positively selected human CD8+ T cells (purity > 99%) from healthy donors were used as effector cells, and B7-1-transfected or nontransfected U251 human glioma cells (U251-B7 or U251-Vec.) were used as stimulator cells. In mixed lymphocyte culture (MLC) with PBLs and U251 cells, nonspecific natural killer (NK) activity was raised by addition of IL-12, and the effect of B7 costimulation was not observed. However, in MLC with CD8+ T cells, efficient proliferation, generation of CTLs, and cytokine production were induced by MLC with U251-B7 in the presence of IL-12. Efficient generation of CTLs was not induced by either MLC with U251-B7 alone or the addition of IL-12 alone. Our results indicate that a combination of B7-1 costimulation and IL-12 is effective for inducing generation of CTLs, and that the CD8+ T cells can be differentiated into CTLs without the help of CD4+ T cells or antigen-presenting cells or both.

B7-1 Antigen↗
PubMed1997

Carnitine depletion during total parenteral nutrition despite oral L-carnitine supplementation.

Carnitine CAR) plays an important role in the beta-oxidation of fatty acids. Less attention. however, has been paid to CAR compared to other nutrients even in total parenteral nutrition (TPN). To examine CAR metabolism during TPN and the effect of simultaneous oral L-CAR supplementation on CAR levels, the blood CAR level was measured in a 3-year-old boy receiving long-term TPN because of short bowel syndrome. Both the total and acyl CAR in the serum were evaluated under various nutritional conditions including oral supplementation of L-CAR. Low CAR concentrations were observed especially when lipid containing TPN regimens were in place. Oral L-CAR supplementation was not sufficient to restore the low CAR levels in the present index patient even when the dose was increased to 120 mg/kg in accordance with the result of the L-CAR absorption test that revealed poor intestinal absorption of this nutrient. Moreover, a markedly low CAR level was measured during the onset of sepsis in the patient, and the blood CAR was depleted when lipid metabolism was activated by lipid loading or sepsis. To date, the late effects of CAR depletion on child growth have not been well examined. It is recommended that the blood CAR level be maintained at normal levels before any prominent manifestations of the deficiency have developed. The intravenous administration of CAR appears to be necessary to supply a sufficient amount of CAR for patients with severe malabsorption.

Administration, Oral↗
PubMed1997

Second generation hepatitis C virus antibody-positive rate in children: investigation of the route of hepatitis C virus infection in children with no history of transfusion.

Hepatitis C virus (HCV) antibody and HCV-RNA screening was undertaken in 1864 children, aged from 0 to 15 years who did not have a history of transfusion. Anti-HCV was tested by the second generation enzyme-linked immunosorbent assay (ELISA). HCV RNA was examined by reverse transcriptase-nested polymerase chain reaction (PCR). Two of the 1864 children were positive for serum HCV RNA. They had no history of transfusion, no episodes of horizontal transmission, but the mother in each case was positive for serum HCV RNA, implying mother-to-infant infection. Eleven children who were positive for HCV antibody with low values and negative for serum HCV RNA were classified as belonging to the high bovine milk (composed primarily of casein)-specific IgG4 value group. This suggested that many of the children who were falsely positive for HCV antibody using ELISA had antibodies to casein.

Adolescent↗
PubMed1997

Pre-operatively determined prognostic factors in metastatic renal cell carcinoma.

OBJECTIVES: The aim of this study was to clarify the pre-operatively determined factors affecting the prognosis in patients with metastatic renal cell carcinoma (RCC). METHODS: We analyzed 69 patients with metastatic RCC who received nephrectomy. Multivariate analysis by Cox's proportional hazards model and survival studies were applied. RESULTS: Tumor thrombus in a renal vein or vena cava was the most significant poor-prognostic factor, followed by multiple-organ metastases and three or more abnormal findings of factors related to acute-phase proteins, in this order. Seven patients having these three risk factors died of cancer within 7 months after nephrectomy. On the other hand, half of the patients without risk factors survived for more than 2 years. CONCLUSIONS: Risk status should be used for selection of metastatic-RCC patients for treatment of the primary site.

Acute-Phase Proteins↗