PubMed Health⌕ Search

Biomedical subjects

Y Kaneko

Publications and source records attributed to Y Kaneko.

At least 19 recordsLinked to original sources
PubMed1995

Gene therapy of hepatoma: bystander effects and non-apoptotic cell death induced by thymidine kinase and ganciclovir.

A retroviral vector carrying herpes simplex virus thymidine kinase gene was constructed, and transfected into the psi 2 packaging cells. The replication-defective retrovirus produced by this cell line (psi 2 tkn cells) was transduced into XC rat hepatoma cells, from which a cell line (XCtkn2) highly sensitive to ganciclovir was cloned. Ganciclovir suppressed the growth of XCtkn2 hepatoma and psi 2tkn cells. Both of these HSV-tk-carrying cells treated with ganciclovir showed potent 'bystander effect' on co-culturing with genetically unmodified XC hepatoma cells. In addition, intratumoral injection of XCtkn2 and psi 2tkn cells into the XC hepatomas transplanted in nude mice and subsequent ganciclovir administration suppressed in vivo growth of the hepatomas. Flow cytometry disclosed that the ganciclovir-treatment increased the relative number of XCtkn2 hepatoma and psi 2tkn cells at the G2 phase of the cell cycle. However, the nuclear fragmentation and internucleosomal DNA cleavage were not observed, indicating that the death of XCtkn2 hepatoma and psi 2tkn cells treated with ganciclovir was not apoptotic.

Animals↗
PubMed1995

CAM--a novel immunosuppressive agent.

This is an initial study of the immunosuppressive efficacy of CAM, a derivative of mycophenolic acid, in a rat heart allograft model when the major histocompatibility complex was fully incompatible, and its effect in improving heart allograft survival compared with mycophenolate mofetil (MMF, RS-61443). CAM or MMF was administered orally from day 1 following the allografting for 40 days. The median survival times (MST) were 6 days in rats with no immunosuppressive drug (control group; n = 6), 83 days with CAM 10 mg/kg (n = 6), and > 100 days with both 20 mg/kg (n = 7), and 30 mg/kg (n = 10). With MMF, in contrast, MST was 9, 17, 35, days with 10, 20, 30 mg/kg/day, respectively. All grafts in the CAM 30 mg/kg-treated group survived for more than 100 days after grafting, and, furthermore, CAM was also more effective than MMF in prolongation of the heart graft survival in rats at each dose. Rats with long-surviving cardiac allografts (30 mg/kg; CAM) accepted skin grafts from the donor-strain but rejected them from the third-party strain, suggesting that donor-specific tolerance was induced by CAM. In the tolerant rats, proliferative response against donor-type alloantigen was not impaired as compared with naive WKAH rats. In contrast, CML assay showed that T cells obtained from the rats bearing permanently accepted F344 heart grafts had less cytotoxic activity to the donor-type target, and the frequency of CTL precursor against donor-type alloantigen was also reduced.

Animals↗
PubMed1995

Apoptosis and nuclear levels of p53 protein and proliferating cell nuclear antigen in human hepatoma cells cultured with tumor promoters.

Anticancer drugs etoposide and mitomycin C increased nuclear p53 protein and decreased proliferating cell nuclear antigen (PCNA) of PLC/PRF/5 human hepatoma cells. These changes were followed by DNA fragmentation and apoptosis. Teleocidin antagonized both apoptosis and alterations of nuclear p53 protein and PCNA induced by these anticancer drugs. In contrast, thapsigargin antagonized only drug-induced nuclear accumulation of p53 protein. Therefore, the inhibition of apoptosis appears not to be the common mechanism of tumor promotion. Both tumor promoters suppressed the increase in nuclear p53 protein, suggesting that an inadequate DNA repair due to the reduced nuclear accumulation of p53 protein might be playing important role in enhancing carcinogenesis.

Apoptosis↗
PubMed1995

Presence of alternative 5' untranslated sequences and identification of cells expressing ctk transcripts in the brain and testis.

From a mouse brain cDNA library, two species of the Csk-type tyrosine kinase (ctk) gene containing different 5' untranslated sequences were cloned. Using the common as well as specific nucleotide sequences of the two clones as probes, we examined the expression of ctk in various mouse tissues by Northern blot analysis. The results indicated that both species of ctk were expressed in the brain, testis and bone marrow. By in situ histochemistry of the brain, ctk transcript was detected in neurons throughout the entire brain, especially those of the cortex, the hippocampus and the cerebellum. This distribution pattern is similar to that of the Src family kinases including Yes, Src, Fyn and Lyn. In the testis, the major transcript (0.7 kb) was shorter than that expressed in the brain and the bone marrow (2.0 kb). A subsequent Northern blot analysis of fractionated germ cell populations and in situ histochemistry revealed that the short and long transcripts were expressed in germ cells and somatic cells, respectively, and that the expression level was quantitatively regulated during germ cell development. These results suggest that Ctk is involved in the regulation of neural function and differentiation of male germ cells through interactions with member(s) of the Src family kinases.

Alternative Splicing↗
PubMed1995

Enhanced expression of multiple protein tyrosine phosphatases in the regenerating mouse liver: isolation of PTP-RL10, a novel cytoplasmic-type phosphatase with sequence homology to cytoskeletal protein 4.1.

To elucidate the role that protein tyrosine phosphatase (PTPs) may play in liver regeneration, PTPs expressed in the mouse liver after partial hepatectomy (PH) were investigated by a PCR-based cloning method. Sequencing of 115 cDNA clones identified 10 different sequences including MPTP (T cell PTP), PTP-1B, PTP-P19, mR-PTP mu, R-PTP alpha, PTP NE-3 (PTP-P1), R-PTP-kappa and the murine homologue of human LAR. The remaining two sequences, PTP-RL9 and PTP-RL10, encoded novel PTPs. PTP-RL10 cDNA contained an open reading frame of 1176 amino acids with no apparent membrane-spanning region. The amino-terminal region had sequence homology to those of human erythrocyte protein 4.1 and ezrin, cytoskeletal proteins. In the regenerating liver, the levels of five PTP gene mRNAs (MPTP, PTP-P19, R-PTP alpha, LAR homologue, and PTP-RL9) increased within 6 h, decreased to the normal level by 24 h, and increased again at 48 to 72 h after PH. The levels of PTP-1B and R-PTP-kappa mRNAs peaked within 6 h, decreased gradually, and returned to the normal level by 168 h after PH. In contrast, the levels of two PTP mRNAs (mR-PTP mu and PTP-RL10) peaked at 48 to 72 h, and returned to the normal level by 168 h after PH. No expression of PTP NE-3 was detected in the liver by Northern blotting. The differential expression of multiple PTPs during the pre-replicative and post-replicative stages of liver regeneration suggests that PTPs are involved in the regulation of growth and differentiation of liver cells.

Amino Acid Sequence↗
PubMed1995

The maize brittle 1 gene encodes amyloplast membrane polypeptides.

A chimeric protein, formed of 56 amino acids from the carboxy terminus of the maize (Zea mays L.) wild-type Brittle1 (Bt1) protein fused to the glutathione-S-transferase gene, was synthesized in Escherichia coli, and used to raise antibodies. Following affinity purification, the antibodies recognized a set of 38- to 42-kDa proteins in endosperm from wild-type Bt1 plants, as well as from brittle2, shrunken2 and sugary1 plants, but not in mutant bt1 endosperm. Bt1 proteins were not detected with the preimmune antibodies. A low level of Bt1-specific proteins was detected at 10 d after pollination (DAP) and increased to a plateau at 16 DAP. At the same time, the ratio of slow- to fast-migrating forms of the protein decreased. During endosperm fractionation by differential centrifugation and membrane sedimentation in sucrose gradients, the Bt1 proteins co-purified with the carotenoid-containing plastid membranes. They were localized to amyloplasts by electron-microscopic immunocytochemistry; most of the signal was detected at the plastid periphery. These results are consistent with predictions made from the deduced amino-acid sequence and previous in-vitro experiments that the bt1 locus encodes amyloplast membrane proteins.

Antibodies↗
PubMed1995

Clonal and non-clonal karyotypically abnormal cells in haemophagocytic lymphohistiocytosis.

We studied chromosomes in bone marrow (BM) or peripheral blood cells of nine patients with haemophagocytic lymphohistiocytosis (HLH); three of them had a family history of HLH and four others underwent concurrent Epstein-Barr virus (EBV) infection. In addition to a large population of normal mitotic cells, karyotypically abnormal clonal cells were found in two patients, abnormal clonal cells and a nonclonal (single) abnormal cell in one, and nonclonal abnormal cells in three. All the six patients with chromosome abnormalities died of progressive disease; one of them also had EBV infection and EBV-associated clonal proliferation. Two of three patients with EBV infection and only normal mitotic cells in BM completely recovered from the disease. Although HLH did not show histological and/or haematological evidence of a neoplastic disease, clonal chromosome abnormalities and the fatal clinical outcome found in some of the patients suggest that the disease may be heterogenous and include malignancy. HLH patients with karyotypically abnormal clonal cells in BM should warrant more intensive chemotherapy than that presently being applied to them and should be considered as candidates for BM transplantation.

Adolescent↗
PubMed1995

Expression of Gal beta 1,4GlcNAc alpha 2,6-sialyltransferase and alpha 2,6-linked sialoglycoconjugates in normal human and rat tissues.

We performed histochemical studies on normal human and rat tissues using anti-Gal beta 1,4GlcNAc alpha 2,6-sialyltransferase (alpha 2,6-ST) antibody and Sambucus nigra agglutinin (SNA). alpha 2,6-ST and its products were detected in almost all tissues examined. However, the staining intensities varied significantly with different cell types. Some secretory epithelial cells, such as hepatocytes and choroid plexus cells, were vividly stained with either anti-alpha 2,6-ST or SNA. In several cell types the intensity of alpha 2,6-ST staining did not always correlate with SNA stainability. Neurons and gastrointestinal epithelia were rarely stained with SNA, even though they were positive for alpha 2,6-ST. In contrast, the endothelial cells of blood vessels strongly reacted with SNA despite their weak alpha 2,6-ST expression. The precise physiological roles played by alpha 2,6-linked sialylated glycoconjugates have been unclear. However, the findings described here lend further support to their important role in cell growth and differentiation, since immature blood cells, including megakaryocytes in bone marrow, were intensely stained with anti-alpha 2,6-ST and SNA, and SNA reaction products were primarily observed in the basal and suprabasal layers of the stratified epithelia rather than in the more differentiated upper layers. In view of the vivid reactivity of anti-alpha 2,6-ST in the decidual cells of the placenta, it seems likely that alpha 2,6-ST expression is under hormonal control.

Adult↗
PubMed1995

Takayasu's arteritis in prepulseless stage manifesting lymph node swelling and hepatosplenomegaly.

A 17-year-old male had fever of unknown origin (FUO) for 3 months with positive c-reactive protein, lymph node swelling, and hepatosplenomegaly. Biopsy specimens of the liver and lymph node disclosed nonspecific inflammation. Lymph node swelling and hepatosplenomegaly subsided gradually, while vascular murmur and pulselessness appeared. Computerized tomography and magnetic resonance imaging showed thickened arterial wall, while angiography disclosed arterial narrowing. From these findings he was diagnosed to have Takayasu's arteritis. The therapy with prednisolone was effective. Takayasu's arteritis is rarely manifested by hepatosplenomegaly and lymphadenopathy in its prepulseless stage.

Adolescent↗
PubMed1995

Somatostatinoma of the pancreas associated with von Hippel-Lindau disease.

A 39-year-old man was admitted because of lumbago, vomiting and massive gastrointestinal bleeding. Oliguria developed a few days later, which was followed by hyperkalemia and cardiac arrest. Autopsy disclosed multiple renal cell carcinomas with diffuse metastasis to the liver, adrenal gland, psoas muscle and vertebrae. In addition, a somatostatinoma was found in the pancreas. From these findings and past history of cerebellar hemangioblastoma and spinal hemangioma he was diagnosed to have von Hippel-Lindau disease. Von Hippel-Lindau disease with islet cell tumor is very rare and is reported here with a review of literature.

Adult↗
PubMed1995

Severe hyponatremia and hyperkalemia induced by trimethoprim-sulfamethoxazole in patients with Pneumocystis carinii pneumonia.

An antimicrobial agent trimethoprim-sulfamethoxazole (Tmp-Smx) does not usually cause electrolyte disturbances at regular doses, and few cases of Tmp-Smx-induced electrolyte imbalance have been reported in the English-language literature to date. Recently, however, we treated two patients with Pneumocystis carinii pneumonia who developed severe hyponatremia and hyperkalemia on administration of high-dose Tmp-Smx. These electrolyte disturbances were attributable to the direct effect of Tmp-Smx on the renal distal tubules, were reversible, and corrected by infusion of a sodium-enriched and potassium-free liquid. Therefore, it is suggested that even after electrolyte disturbances have occurred, high-dose Tmp-Smx therapy may be continued for severe infectious diseases under appropriate electrolyte correction.

Humans↗
PubMed1995

A late-appearing Philadelphia chromosome in acute lymphoblastic leukemia confirmed by expression of BCR-ABL mRNA.

We report two cases of acute lymphoblastic leukemia (ALL) with a late-appearing Philadelphia chromosome (Ph1), confirmed by the expression of BCR-ABL mRNA, using the reverse transcriptase/polymerase chain reaction (RT/PCR) technique. The first patient was a 10-year-old boy with precursor B cell type ALL-L1 (FAB classification). At diagnosis, no metaphase cells were found by chromosome analysis and BCR-ABL mRNA was not observed. At the beginning of relapse, which occurred after 7 months of complete remission, a normal karyotype was observed. At the terminal stage, leukemic cells with Ph1 and BCR-ABL mRNA for the P190 variety were observed. The second patient was a 12-year-old boy with immature T cell type ALL-L1. The metaphase cells showed a 9p- chromosome at diagnosis and Ph1 appeared in addition to 9p- at relapse. Hybrid mRNA for the P210 variety was detected only when Ph1 had developed. The blast cells with Ph1 were derived from the original leukemic clone through clonal evolution, since the same clonal rearrangements of IGH or TCRB were detected in leukemic cells obtained both at diagnosis and relapse in both patients. Thus, in both cases, Ph1 was detected only in the course of ALL along with expression of BCR-ABL mRNA. This observation also confirmed that, as in de novo Ph1-positive ALL, both the P190 and P210 varieties of BCR-ABL mRNA are observed in ALL with late-appearing Ph1.

Base Sequence↗
PubMed1995

Antagonistic peptides against human anaphylatoxin C5a.

Multivalent synthetic peptides derived from C5a were prepared in order to examine their effects on the C5a receptor (C5aR). Multiple antigen peptide (MAP) of the C5a C-terminal region (MAP61-74) bound to cells expressing C5aR with high affinity. On the other hand, N-terminal peptides (MAP3-16 and MAP12-26) and one with a sequence from the mid-portion of C5a (MAP37-53) did not bind to the cells. In addition, MAP61-74 inhibited Ca2+ mobilization and release of beta-hexosaminidase by C5a from dibutyryl cAMP-activated U937 cells. This Ca2+ mobilization was also inhibited by MAP12-26 and Mono61-74, the monomeric C-terminal peptide. Taken together, these data indicate that C5a binds to the C5aR via its C-terminal region. Furthermore, MAP61-74, a 14mer peptide that has additional amino acids at the N-terminal compared with the C-terminal octapaptide, can bind to C5aR and can be considered an antagonist of C5a which may prove useful as an agent for controlling the allergic response caused by complement activation.

Amino Acid Sequence↗
PubMed1995

[Bronchogenic carcinoma associated with right aortic arch and postaortic left brachiocephalic vein--report of a case].

61-year-old male was admitted to our hospital for surgical treatment of bronchogenic squamous cell carcinoma arising from left B8. The patient had right aortic arch with aberrant left subclavian artery and postaortic left brachiocephalic vein. Intraoperatively, left ligamentum arteriorsus forming vascular ring between the left subclavian artery and the pulmonary artery was found, however the ligamentum arteriorsus was not divided because no symptom of esophago-tracheal compression was observed. The left brachiocephalic vein was located between the ascending aorta and the arterial ligament. The lower lobe of the left lung was resected, and lymph nodes in the left side of the mediastinum were dissected easily because the aortic arch was positioned on the other side. Preoperative assessment of the type of branching and the course of arteries and veins is important for safe operation.

Aorta, Thoracic↗
PubMed1995

[New tactile sensor for thoracoscopic detection of intrapulmonary nodules].

We have developed a new tactile sensor which can be used for thoracoscopic detection of invisible intrapulmonary nodules. We applied this new device for consecutive ten cases to excise twelve intrapulmonary nodules thoracoscopically from August 1994 to January 1995. In this report, one of ten cases was presented. The patient was a forty-three-year-old female and admitted with an indeterminate nodule on chest X-ray and computed tomography. When the sensor probe quantifying the hardness of objects by the changes in resonance frequency of the sensor (delta f) passed above the nodule, a sudden jump was evoked in delta f curve on the computer screen. The nodule was resected thoracoscopically and proved pathologically to be adenocarcinoma. Thoracoscopic procedure was then converted to open thoracotomy and lobectomy with lymph node dissection was performed.

Adenocarcinoma↗