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Biomedical subjects

K Kanbe

Publications and source records attributed to K Kanbe.

At least 19 recordsLinked to original sources
PubMed2004

Synovectomy reduces stromal-cell-derived factor-1 (SDF-1) which is involved in the destruction of cartilage in osteoarthritis and rheumatoid arthritis.

We have compared the concentrations of stromal-cell-derived factor-1 (SDF-1), matrix metalloproteinase-1 (MMP-1), MMP-9 and MMP-13 in serum before and after synovectomy or total knee replacement (TKR). We confirmed the presence of SDF-1 and its receptor CXCR4 in the synovium and articular cartilage by immunohistochemistry. We established chondrocytes by using mutant CXCR4 to block the release of MMPs. The level of SDF-1 was decreased 5.1- and 6.7-fold in the serum of patients with OA and RA respectively, after synovectomy compared with that before surgery. MMP-9 and MMP-13 were decreased in patients with OA and RA after synovectomy. We detected SDF-1 in the synovium and the bone marrow but not in cartilage. CXCR4 was detected in articular cartilage. SDF-1 increased the release of MMP-9 and MMP-13 from chondrocytes in a dose-dependent manner. The mutant CXCR4 blocked the release of MMP-9 and MMP-13 from chondrocytes by retrovirus vector. Synovectomy is effective in patients with OA or RA because SDF-1, which can regulate the release of MMP-9 and MMP-13 from articular chondrocytes for breakdown of cartilage, is removed by the operation.

Aged↗
PubMed2000

A putative G protein-coupled receptor, RDC1, is a novel coreceptor for human and simian immunodeficiency viruses.

More than 10 G protein-coupled receptors (GPCRs) have been shown to act as coreceptors for infection of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We have isolated HIV-1 variants infectious to primary brain-derived CD4-positive cells (BT-3 and BT-20/N) and U87/CD4 glioma cells that are resistant to T-cell line-tropic (T-tropic), macrophage-tropic (M-tropic), and T- and M-tropic (dualtropic) (X4, R5, and R5X4) HIV-1 strains. These primary brain-derived cells were also highly susceptible to HIV-2(ROD), HIV-2(SBL6669), and SIV(mndGB-1). A factor or coreceptor that determines the susceptibility of these brain-derived cells to these HIV and SIV strains has not been fully identified. To identify this coreceptor, we examined amino acid sequences of all known HIV and SIV coreceptors and noticed that tyrosine residues are well conserved in their extracellular amino-terminal domains. By this criterion, we selected 18 GPCRs as candidates of coreceptors for HIV and SIV strains infectious to these brain-derived cells. mRNA expression of an orphan GPCR, RDC1, was detected in the brain-derived cells, the C8166 T-cell line, and peripheral blood lymphocytes, all of which are susceptible to HIV-1 variants, but not in macrophages, which are resistant to them. When a CD4-expressing cell line, NP-2/CD4, which shows strict resistance to infection not only with HIV-1 but also with HIV-2 or SIV, was transduced with the RDC1 gene, the cells became highly susceptible to HIV-2 and SIV(mnd) strains but to neither M- nor T-tropic HIV-1 strains. The cells also acquired a low susceptibility to the HIV-1 variants. These findings indicate that RDC1 is a novel coreceptor for several HIV-1, HIV-2, and SIV strains which infect brain-derived cells.

Animals↗
PubMed1999

A CXC chemokine receptor, CXCR5/BLR1, is a novel and specific coreceptor for human immunodeficiency virus type 2.

G protein-coupled receptors serve as coreceptors in the infection process of human immunodeficiency virus type-1 (HIV-1), type-2 (HIV-2), and simian immunodeficiency virus (SIV). In this study, we showed that a CXC-CKR, CXCR5/BLR1, is a novel coreceptor for HIV-2, but for neither HIV-1 nor SIV. The expression of CXCR5 was detected by polymerase chain reaction after reverse transcription of cellular mRNA from S+L-HOS/CD4 cells and MT-2 human T cells, and the CXCR5 gene was cloned into an expression vector. S+L-HOS/CD4 cells were susceptible to several HIV-2 strains but not most HIV-1 strains. To examine a coreceptor activity of CXCR5, we used NP-2/CD4, which is a human glioma cell line, NP-2, transduced with the CD4 gene that shows strict resistance to infection with HIV-1, HIV-2, SIVmac, SIVagm, or SIVmnd strain. When CXCR5 was transduced into NP-2/CD4 cells, they became highly susceptible to HIV-2ROD and HIV-2CBL23 strains in a CD4-dependent manner but to not to HIV-1 or SIV strains. Anti-CXCR5 monoclonal antibody and a ligand for CXCR5, BCA-1, inhibited HIV-2 infection to NP-2/CD4/CXCR5 cells. Our findings suggest a possibility that CXCR5/BLR1 serves as a coreceptor for HIV-2 strains in vivo.

Animals↗
PubMed1999

Changes in and discrepancies between cell tropisms and coreceptor uses of human immunodeficiency virus type 1 induced by single point mutations at the V3 tip of the env protein.

We examined the effect of amino acid substitutions of the GPGR (glycine-proline-glycine-arginine) tip sequence at the V3 domain of the Env protein of human immunodeficiency virus type 1 (HIV-1) on its cell tropism and coreceptor use. We changed the GPGR sequence of a T-cell line (T)- and macrophage (M)-tropic (R5-R3-X4) HIV-1 strain, GUN-1wt, to GA(alanine)GR (the resulting mutant was designated GUN-1/A), GL(leucine)GR (GUN-1/L), GP(proline)GR (GUN-1/P), GR(arginine)GR (GUN-1/R), GS(serine)GR (GUN-1/S), or GT(threonine)GR (GUN-1/T). GUN-1/A, GUN-1/S, and GUN-1/T mutants infected brain-derived cells such as a CD4-transduced glioma cell line, U87/CD4, and a brain-derived primary cell strain, BT-20/N, as well as T-cell lines in a CD4-dependent manner, although the plating of these mutants onto macrophages was inhibited. GUN-1/L, GUN-1/P, and GUN-1/R mutants showed both T- and M-tropism, but did not plate onto the brain-derived cells. A CCR3, CCR5, CCR8, or CXCR4 gene was introduced into a CD4-positive glioma cell line, NP-2/CD4, which demonstrated complete resistance to various HIV-1 strains. Not only HIV-1 strains, which were infectious to macrophages, such as GUN-1wt, GUN-1v, GUN-1/L, and GUN-1/P, but also an HIV-1 strain, GUN-1v, which was hardly infectious to macrophages, grew well in NP-2/CD4 cells expressing CCR3 or CCR5. However, the M-tropic GUN-1/R mutant could not efficiently use CCR5 nor CCR3. No point mutants, except GUN-1/L, grew well in NP-2/CD4 cells expressing CCR8. These findings indicate that the cell tropism of HIV-1 to macrophages and brain-derived cells and their use of the coreceptors were markedly, though not always concomitantly, affected by the tip sequence of the V3 domain.

Brain↗
PubMed1999

Establishment of a new system for determination of coreceptor usages of HIV based on the human glioma NP-2 cell line.

CD4 and one of the G-protein-coupled receptors (GPCRs) on the cell surface function as a receptor and a coreceptor, respectively, in infection of cells with human and simian immunodeficiency viruses (HIV/SIV). To determine which GPCRs can be coreceptors for HIV (HIV-1 and HIV-2) or SIV infection, several cell lines, including human osteosarcoma HOS-T4 cells and human glioma U87/CD4 cells, have been used. However, these cells often show susceptibilities to some HIV or SIV strains before transduction of GPCRs. The results of this study showed that a CD4-transduced human glioma cell line, NP-2/CD4, a human erythroleukemia cell line, K562/CD4, and a human ovarian cancer cell line, TYK/CD4, were completely resistant to the HIV-1 and HIV-2 strains tested. After transduction of several GPCRs into NP-2/CD4, K562/CD4, or TYK/CD4 cells, NP-2/CD4 cells but not K562/CD4 or TYK/CD4 cells mostly showed expected susceptibilities to several HIV strains. Therefore, an NP-2 cell system would be useful to determine the coreceptor usage of HIV isolates, to find a new coreceptor for HIV/SIV, and to analyze the early stages of HIV/SIV infection.

Base Sequence↗
PubMed1999

An orphan G protein-coupled receptor, GPR1, acts as a coreceptor to allow replication of human immunodeficiency virus types 1 and 2 in brain-derived cells.

Twelve G protein-coupled receptors, including chemokine receptors, act as coreceptors and determinants for the cell tropisms of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We isolated HIV-1 variants from T-cell-line (T)- and macrophage (M)-tropic (i.e., dualtropic) (R5-R3-X4) HIV-1 strains and also produced six HIV-1 mutants carrying single-point amino acid substitutions at the tip of the V3 region of the Env protein of HIV-1. These variants and three mutants infected brain-derived CD4-positive cells that are resistant to M-, T-, or dualtropic (R5, X4, or R5-X4) HIV-1 strains. However, a factor that determines this cell tropism has not been identified. This study shows that primary brain-derived fibroblast-like cell strains, BT-3 and BT-20/N, as well as a CD4-transduced glioma cell line, U87/CD4, which were susceptible to these HIV-1 variants and mutants and the HIV-2ROD strain, expressed mRNA of an orphan G protein-coupled receptor (GPCR), GPR1. When a CD4-positive cell line which was strictly resistant to infection with diverse HIV-1 and HIV-2 strains was transduced with GPR1, the cell line became susceptible to these HIV-1 variants and mutants and to an HIV-2 strain but not to T- or dualtropic HIV-1 strains, and numerous syncytia formed after infection. These results indicate that GPR1 functions as a coreceptor for the HIV-1 variants and mutants and for the HIV-2ROD strain in vitro.

Brain↗
PubMed1998

Analysis of muscle bioenergetic metabolism in rabbit leg lengthening.

The effect of lengthening on muscle metabolism was measured and correlated to the percent lengthening at early and late time points. Using the rabbit tibial lengthening model, the authors examined the effects of lengthening on the tibialis anterior muscle using phosphorus-31 magnetic resonance spectroscopy. Thirty-six rabbits were divided into five groups, four groups by percent lengthening (0%, 15%, 20%, and 25%), with each group divided into subgroups of early (end distraction) and late (12 weeks after end distraction), and the fifth group using the opposite untreated leg as control. Several parameters measuring metabolism of muscle using phosphorus-31 magnetic resonance spectroscopy analysis were compared. No changes occurred to 15% lengthening, but significant decreases were measured at 20% and 25% lengthening. After a 25% lengthening, the decreased metabolism persisted at 12 weeks after distraction, indicating the possibility of permanent damage. After 20% lengthening, the same parameters improved but never to normal levels. The authors conclude that lengthening to 15% is safe for muscle, but 20% to 25% lengthening may result in permanent metabolic damage. The current study also suggests that phosphorus-31 magnetic resonance spectroscopy may provide a viable clinical method for evaluating muscle damage during lengthening.

Adenosine Triphosphate↗
PubMed1995

Apoptosis of a fibrosarcoma induced by protein-free culture involves DNA cleavage to large fragments but not internucleosomal fragmentation.

A murine fibrosarcoma clone, Gc-4 SD, grows depending on fetal calf serum. In MTT assay, protein-free cultivation resulted in a reduction of the viable cell number time-dependently. Electron-microscopic and flow-cytometric analyses revealed that the reduction in growth was accompanied by the appearance of apoptotic cells. However, no internucleosomal fragmentation was observed even after SI-nuclease treatment. On the other hand, pulse field gel electrophoresis revealed that cleavage of DNA into high-molecular-weight fragments estimated as 50 to 150 kilobase pairs (kbp), with a peak of 100 kbp, was found in the serum-deprived cells. Large fragments disappeared from the DNA extracts when the smaller cells with high blue fluorescence with Hoechst 33342 were removed by flow cytometry, suggesting direct correlation between the large DNA fragmentation and apoptosis. The addition of aurintricarboxylic acid neither abolished the large DNA fragmentation nor inhibited the reduction in the number of viable cells. Both cycloheximide and actinomycin D enhanced the reduction in the number of viable cells as well as the large DNA fragmentation. These results suggest that apoptosis of a fibrosarcoma induced by protein-free culture involves a specific endogenous endonuclease, which may be distinct from and independent of the ATA-sensitive endonuclease producing internucleosomal DNA fragmentation.

Animals↗
PubMed1995

Multiple neurilemmoma in both legs. A case report.

A Japanese man, who was 61 years of age, presented with multiple neurilemmoma in both legs which had arisen from different levels of both sciatic nerves. There were no clinical findings relating to von Recklinghausen's disease in the patient or his siblings. Multiple neurilemmoma may be the result of embryonic metameric anomalies. The condition may be distinguished from von Recklinghausen's disease by the distribution of the lesions and genetic analysis.

Humans↗
PubMed1995

Interferon-gamma and the induction of protective IgG2a antibodies in non-lethal Plasmodium berghei infections of mice.

Mice treated with anti-IFN-gamma monoclonal antibodies were unable to recover from infection with an attenuated variant of P. berghei (Pb XAT) which causes non-lethal malaria in normal mice. On the other hand, treatment with anti-IL-4 monoclonal antibodies had no effect on the course of infection. IFN-gamma was produced by spleen cells in vitro during the early phase of the infection. Treatment with anti-IFN-gamma suppressed development of an anti-plasmodial IgG2a immunoglobulin isotype in the serum of infected mice whereas anti-IL-4 interfered with the IgG1 response. An IgG2a fraction of immune serum collected from mice that had recovered from Pb XAT transferred immunity to naive mice but the IgG1 fraction did not. When glutaraldehyde fixed parasitized erythrocytes were incubated with immune serum in suspension, specific IgG2a antibodies were detected by fluorescein staining on the membranes of cells infected with mature stages of parasites. These results indicate that IFN-gamma is a key to inducing B cells to produce the protective antiplasmodial IgG2a immunoglobulin isotype. Antibody-dependent cell-mediated parasite killing seems to be involved in the mechanism of recovery from infection with Pb XAT.

Animals↗
PubMed1995

Fracture of the posterior medial tubercle of the talus treated by internal fixation: a report of two cases.

A fracture through the posterior medial tubercle of the talus is quite rare. Although excision of the bone fragments has been reported previously in this fracture, cases of internal fixation of the posterior medial tubercle of the talus have not been reported. Two patients are described who presented with a fracture through the posterior medial tubercle of the talus which was treated with internal fixation. Our patients appeared normal on physical examination and returned to work, with no evidence of avascular necrosis of the fragments.

Adult↗
PubMed1995

Reduction of in vitro clastogenicity induced by the mixture of optical isomers of nadifloxacin during storage.

The fluoroquinolone antibacterial agent, nadifloxacin (NDFX, CAS 124858-35-1), is a racemic compound. The storage effect on the in vitro clastogenicity of a solution of the racemic compound and a mixture solution of the optical isomers of NDFX, prepared by mixing equal amounts of S- and R-enantiomers, was investigated. The potential of NDFX and the enantiomer mixture, prepared from equal amounts of each S- and R-enantiomer, to induce chromosomal aberrations in vitro was investigated in cultured fibroblasts derived from Chinese hamster lung cells immediately, 2 and 4 weeks after preparation of the test solutions (stored at 20 degrees C, protected from light) using 24 h of continuous treatment method. In the results, NDFX did not significantly increase the incidence of chromosomal aberrations at 200 micrograms/ml regardless of the storage period. On the other hand, the mixture significantly increased the incidence of chromosomal aberrations at 200 micrograms/ml immediately after preparation to an extent similar to that of S-enantiomer alone, but the mixture did not do so after 2 and 4 weeks of storage. Neither S- nor R-enantiomer changed the chromosomal aberration inducibility during storage. The content and optical purity of the test substances in each test solution also did not change during storage. These facts suggested that the molecular condition of each optical isomer in the mixture solution became equivalent to that in the racemic solution during storage periods.

Animals↗
PubMed1994

Effects of protein kinase inhibitors on the cell motility stimulated by autocrine motility factor.

Preincubation of Dunn osteosarcoma cells for 1 h with both 100 nM of staurosporine and 10 micrograms/ml of genistein resulted in a significant decrease in the motility stimulated by autocrine motility factor (AMF), whereas these reagents did not affect the basal motility and proliferation at these concentrations. The effect of the agents on the stimulated motility was both dose- and time-dependent. The motility stimulated by the anti-AMF receptor mAb was also inhibited. In contrast, H-8 had a negligible effect upon the stimulated motility. These data suggest that both kinase C and tyrosine kinase play a role in AMF-stimulated cell motility, while protein kinase A, which is selectively associated with the adenylate cyclase pathway, may not be required for the stimulation.

Alkaloids↗
PubMed1994

Differential purification of autocrine motility factor derived from a murine protein-free fibrosarcoma.

We have previously shown that a protein-independent growing fibrosarcoma, Gc-4 PF has a high motile response to its cultured medium, which is associated with an increase in expression of gp78, a cell surface receptor for autocrine motility factor (AMF). Here we show that the cultured medium contains two motile activities, acidic and basic AMFs with regard to binding features on ion exchange chromatography. These two AMFs were purified by sequential DEAE anion exchange, CM cation exchange, and gel filtration chromatographies. However, both acidic and basic AMFs have a similar size of 55 kDa and 65 kDa under non-reducing and reducing conditions, respectively, with the same pI of 6.5. The stimulated motility of both AMFs was inhibited by the pertussis toxin (PT), but not by Streptomyces hyaluronidase. These two AMFs significantly stimulated the lung colonizing properties of the self-producing cells by 1.5-fold. These results suggest that both acidic and basic AMFs may correspond to the previously reported AMF and confirm directly that the AMF-gp78 signaling pathway is involved in cell motility associated with metastatic property.

Animals↗
PubMed1992

[Percutaneous transabdominal whole layer core needle biopsy for staging the urinary bladder cancer].

Accurate staging is one of the most important determinants necessary in planning an effective treatment for bladder cancer, but at the present time, staging by the conventional clinical methods are not completely reliable. Accordingly, we have newly developed a percutaneous transabdominal core needle biopsy technique capable of obtaining good cylindrical specimens of the entire layer. In order to obtain the core specimen of the bladder wall, which is a vesico-elastic material, the biopsy needle must penetrate the bladder wall at an extremely high speed. We have developed an original automatic biopsy instrument and modified the head of needle for this purpose. With this method, we could obtain good core specimens for pathological staging in about 90% cases. The correlation between the pathological stagings of core specimens and those of cystectomy specimens were in good agreement. This technique is accurate not only for preoperative pathological staging, but also monitoring histopathologically the responsiveness of multi-disciplinary treatment for invasive bladder cancer. This method allows us to determine the optimal therapeutic modality for managing individual patient with invasive bladder cancer.

Aged↗