Biomedical subjects

A Kimura

Publications and source records attributed to A Kimura.

At least 19 recordsLinked to original sources

PubMed2002

Localization of matrix proteins of hard tissue in osteochondromas.

We examined 10 cases of osteochondroma by means of histopathological, histochemical and immunohistochemical techniques. The surface of the masses was covered with a cartilage tissue showing positive immunohistochemical reaction for collagen type 2, and the deep region was composed of spongy bone, showing positive immunohistochemical reaction for collagen type 1 and osteocalcin. Between the cartilage and spongy bone, which is a metaphysis-like region, a chondroidal pattern appeared in the matrix of hypertrophy cartilage. In these regions, both type 1 (and osteocalcin) and 2 collagens were immunohistochemically detected. Although there is still no direct evidence, we believe that the cells involved in so-called "chondroid bone" temporally express cartilage phenotypes and then transform directly into bone-forming cells that survive in the chondroid bone until the tissue is resorbed and remodeled. Our examination results suggest that bone formation in osteochondromas, at least in some regions, occurs through transchondroid bone formation.

Adolescent↗

PubMed2002

Electronic structure of YbXCu(4) (X = In, Cd, Mg) investigated by high-resolution photoemission spectroscopy.

The valence-band electronic structure of YbXCu(4) (X = In, Cd, Mg) has been investigated by means of temperature-dependent high-energy-resolution photoemission spectroscopy using a He I resonance line (hnu = 21.22 eV) and synchrotron radiation (hnu = 800 eV). Intensities of the structure due to the Yb(2+) 4f(7/2) states in the He I spectra of YbInCu(4) and YbCdCu(4) gradually increase with decreasing temperature from 300 to 10 K, and Yb(2+) 4f(7/2) structures are clearly observed as peaks near the Fermi level (E(F)) at 10 K. The enhancement of the Yb(2+) 4f(7/2) peak from 50 to 10 K is much greater for YbInCu(4) than for YbCdCu(4). On the other hand, the Yb(2+) 4f(7/2) states of YbMgCu(4) are observed as a broad structure near E(F). In the synchrotron radiation photoemission spectra of YbInCu(4) and YbCdCu(4), the structures due to the Yb(2+) and Yb(3+) 4f states are recognized at all temperatures. The intensity ratio Yb(2+)/Yb(3+) gradually increases with decreasing temperature. The energy separations between the Yb(2+) and Yb(3+) 4f structures of YbInCu(4) increase from 50 to 20 K. For YbMgCu(4), on the other hand, almost only the Yb(2+) structures are observed and little temperature dependence has been detected.

Journal Article↗

PubMed2002

Analysis of HLA in children with gelatin allergy.

Systemic immediate reactions including anaphylaxis to gelatin in vaccines have been reported. However, the number of such reports is very small compared with the number of children exposed to gelatin. The present study was designed to investigate whether susceptibility or resistance to gelatin allergy is associated with human leukocyte antigen (HLA) class II gene. Blood samples were obtained from 49 patients with gelatin allergy and specific IgE to gelatin. DNA-based HLA class II typing was performed to determine the DRB1, DQB1 and DPB1 alleles. Genotype frequencies were compared with those found in 240 unrelated controls. The frequency of DQB1*0303 (55.1%) was significantly higher in the patients than in the control subjects (32.1%). The frequency of DPB1*0402 was also significantly higher in the patients (32.7%) than in the control subjects (15.4%). On the other hand, the frequency of subjects carrying DRB1*15 (DRB1*1501 and DRB1*1502) was significantly lower among the patients group (18.4%) than among the controls (40.8%). We found that DQB1*0303 and DPB1*0402 were positively associated with the IgE response for gelatin, while DRB1*15 was negatively associated with it.

Child↗

PubMed2002

Chromosomal instability and radiosensitivity in myelodysplastic syndrome cells.

Myelodysplastic syndrome (MDS) is a clonal disorder of hematopoietic stem cells. To investigate whether chromosomal instability and/or DNA repair defects are involved in the development of MDS, we measured the micronucleus (MN) frequency in peripheral blood lymphocytes exposed to various doses of X-rays, using a cytokinesis-block micronucleus assay. The spontaneous MN frequencies in RAEB and RAEB-T patients were significantly higher than those in normal individuals (P = 0.0224, P = 0.008, respectively). Also, the X-ray-induced MN frequencies in RA/RARS, RAEB, and RAEB-T patients were significantly higher than those in normal individuals (P = 0.007, P = 0.003, P = 0.003, respectively, at 2 Gy). In order to elucidate the cause of unusual radiosensitivity, we measured the expression levels of nucleotide excision repair (NER) genes in peripheral blood mononuclear cells using a RT-PCR method. Reduction of NER gene expression was found in only one of 10 patients with low risk MDS, but in four of 11 patients with high risk MDS. Our data suggest that chromosomal instability and DNA repair defects may be involved in the pathophysiology of disease progression of MDS.

Adult↗

PubMed2002

Evaluation of three flocculation methods for the purification of Cryptosporidium parvum oocysts from water samples.

AIMS: Evaluation of three flocculation methods for the purification of Cryptosporidium parvum oocysts from tap water. METHODS AND RESULTS: Ferric sulphate, aluminium sulphate and calcium carbonate were compared for their recovery efficiency of C. parvum oocysts from tap water. Lower mean recovery was achieved by calcium carbonate (38.8%) compared with ferric sulphate (61.5%) and aluminium sulphate (58.1%) for the recovery of 2.5 x 10(5) oocysts l(-1); 2.5 oocysts l(-1) and 1 oocyst l(-1) were adequately purified using ferric sulphate flocculation. In vitro excystation experiments showed that ferric sulphate flocculation does not markedly reduce the viability of oocysts. CONCLUSIONS: Ferric sulphate flocculation is a simple and effective tool for the purification of C. parvum oocysts from tap water. SIGNIFICANCE AND IMPACT OF THE STUDY: The high recovery rates and low impact on oocyst viability provided by ferric sulphate flocculation might be useful for the detection of Cryptosporidium oocysts in environmental water samples.

Alum Compounds↗

PubMed2001

The sorbin homology domain: a motif for the targeting of proteins to lipid rafts.

On phosphorylation of Cbl, the c-Cbl-associated protein (CAP)/Cbl complex dissociates from the insulin receptor and translocates to a lipid raft membrane fraction to form a ternary complex with flotillin. Deletion analyses of the CAP gene identified a 115-aa region responsible for flotillin binding. This region is homologous to the peptide sorbin and is referred to as the sorbin homology (SoHo) domain. This domain is present in two other proteins, vinexin and ArgBP2. Vinexin also interacted with flotillin, and deletion of its SoHo domain similarly blocked flotillin binding. The overexpression of a CAP mutant in which the SoHo domain had been deleted (CAPDeltaSoHo) prevented the translocation of Cbl to lipid rafts and subsequently blocked the recruitment of CrkII and C3G. Moreover, overexpression of CAPDeltaSoHo prevented the stimulation of glucose transport and GLUT4 translocation by insulin. These results suggest a mechanism for localization of signaling proteins to the lipid raft that mediates the compartmentalization of crucial signal transduction pathways.

3T3 Cells↗

PubMed2001

A hematopoietic-specific transmembrane protein, Art-1, is possibly regulated by AML1.

The functions of AML1 in hematopoietic differentiation are repressed by AML1-mutants including the AML1/ETO chimeric protein, which is seen in t(8;21) acute myeloid leukemia. Erythroid progenitors of the patients with t(8;21) AML expressed AML1/ETO. To investigate the effect of AML1/ETO in erythroid cells, we made a tetracycline-regulated AML1/ETO overexpression system in mouse erythroleukemic (MEL) cells. Enforced AML1/ETO repressed the terminal erythroid differentiation. Furthermore, we performed representational difference analysis using this MEL cell system to clone the downstream targets of AML1 in erythroid cell differentiation. We cloned a novel transmembrane protein, Art-1 (AML1-regulated transmembrane protein 1), which is a member of tetramembrane spanning superfamily. Art-1 expression was restricted in hematopoietic cells. It was upregulated by AML1 and downregulated by AML1/ETO in both erythroid and myeloid cells, and increased during erythroid cell differentiation. Art-1 may play an important role in the differentiation of erythroid cells, possibly as a direct downstream target of AML1.

Amino Acid Sequence↗

PubMed2001

Arrest of human dendritic cells at the CD34-/CD4+/HLA-DR+ stage in the bone marrow of NOD/SCID-human chimeric mice.

Human dendritic cell (DC) precursors were engrafted and maintained in NOD/SCID- human chimeric mice (NOD/SCID-hu mice) implanted with human cord blood mononuclear cells, although no mature human DCs were detected in lymphoid organs of the mice. Two months after implantation, bone marrow (BM) cells of NOD/SCID-hu mice formed colonies showing DC morphology and expressing CD1a in methylcellulose culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha). The CD34-/CD4+/HLA-DR+ cell fraction in NOD/SCID-hu mouse BM generated CD1a(+) cells that were highly stimulatory in mixed leukocyte reactions in culture with GM-CSF and TNF-alpha. These results suggest a strong potential for NOD/SCID-hu BM to generate human DCs, although DC differentiation may be blocked at the CD34-/CD4+/HLA-DR+ stage. (Blood. 2001;97:3655-3657)

Animals↗

PubMed2001

LEDGF binds to heat shock and stress-related element to activate the expression of stress-related genes.

We have investigated the mechanism by which LEDGF protects cells against environmental stress. Our earlier report showed that a low level of LEDGF was present in the nucleus of most cell types and significant elevation of LEDGF level was induced by heat and oxidative stress. The cells overexpressing LEDGF-activated expression of heat shock proteins and enhanced survival of many cell types. Here we show that LEDGF binds to heat shock element (HSE) and stress-related regulatory element (STRE) to activate the expression of stress-related genes (Hsp27 and alphaB-crystallin). Apparently, HSE and STRE are present in promoters of many stress-related genes. Elevation of many stress-related proteins (STRPs) induced by LEDGF may protect cells against environmental stress. In yeast, it has been demonstrated that a single stress can activate the expression of multiple STRPs. This is known as "cross-protection," and now similar mechanism has been found in mammalian cells and LEDGF plays a vital role in it.

Base Sequence↗

PubMed2001

Isolation of novel heart-specific genes using the BodyMap database.

Two novel heart-specific genes, C3orf3 (chromosome 3 open reading frame 3) and MMGL (myomegalin-like), were isolated using BodyMap, a gene expression database based on site-directed 3' expressed sequence tags (3'-ESTs) which were collected from nonbiased cDNA libraries of various tissues. The cDNA of C3orf3 was 1667 bp and was composed of 12 exons within a 10-kb-long genomic sequence. MMGL consisted of 8 exons within a genomic sequence of over 70 kb, leading to four alternatively spliced transcripts. Both genes were strongly expressed in heart and also in skeletal muscle. C3orf3 and MMGL were mapped to 3p22 and 1q1, respectively. Subcellular localizations of their putative proteins were determined as being in the cytoplasm for C3orf3 and in the cytoplasm and nucleus for MMGL. This study showed that BodyMap is a useful database for the isolation of tissue-specific genes.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Expression and localization of transcripts of MT5-MMP and its related MMP in the ovary of the medaka fish Oryzias latipes.

cDNA clones of MT5-matrix metalloproteinase (MT5-MMP) and a related protein (designated MT5-MMP-del) were isolated by screening the cDNA library and by 3'-rapid amplification of cDNA ends using an ovary RNA of the medaka fish Oryzias latipes. The MT5-MMP clone encodes a protein of 546 amino acids while the MT5-MMP-del clone encodes a protein of 431 amino acids. Compared with mammalian counterparts, the fish MT5-MMP and MT5-MMP-del both lack the signal peptide and a part of the prodomain. The fish MT5-MMP and MT5-MMP-del were different in that the latter did not have the stem/transmembrane/cytoplasmic domain. The two fish MMPs were expressed in the ovary, testis, brain, and intestine. In the ovary, MT5-MMP mRNA was expressed in the oocytes of small growing follicles. In contrast, MT5-MMP-del mRNA was found in the stromal interstitial cells. These results strongly suggest that a MT5-MMP/gelatinase A cascade may possibly operate in the process of spawning and/or other events associated with ovulated oocytes or fertilized eggs of the medaka fish.

3' Untranslated Regions↗

PubMed2001

Sporadic Campylobacter jejuni infections in Hawaii: associations with prior antibiotic use and commercially prepared chicken.

Campylobacter is the most common cause of bacterial foodborne illness in the United States, and Hawaii has the highest rate of Campylobacter jejuni infections in the nation. A case-control study was conducted to determine indigenous exposures that contribute to the high incidence of sporadic C. jejuni infection in Hawaii. A total of 211 case patients with diarrhea and confirmed Campylobacter infection was enrolled, along with 1 age- and telephone exchange-matched control subject for each patient. Participants were interviewed about illness, medicines, food consumption, food-handling practices, and exposure to animals. In matched logistic regression analyses, eating chicken prepared by a commercial food establishment in the 7 days before case illness onset (adjusted odds ratio [AOR], 1.8; P=.03) and consuming antibiotics during the 28 days before illness onset (AOR, 3.3; P=.03) were significant independent predictors of illness. Further study of the association of Campylobacter illness with commercially prepared chicken and prior antibiotic use is needed.

Animals↗

PubMed2001

A second susceptibility gene for developing rheumatoid arthritis in the human MHC is localized within a 70-kb interval telomeric of the TNF genes in the HLA class III region.

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease with a multifactorial genetic basis. However, pathogenic genes for RA other than the human leukocyte antigen (HLA)-DRB1 gene have yet to be identified. Here, we investigated whether there is a second susceptibility locus for RA within the human major histocompatibility complex using 18 microsatellite markers distributed from the centromeric (HSET) to the telomeric end (P5-15) of the 3.6-Mb HLA region. Statistical studies of associated alleles on each microsatellite locus showed that one pathogenic gene for RA in the HLA region is localized in the DRB1 gene, as expected. Further, a second susceptibility gene of RA was suggested to be present in the HLA class III region, narrowed to 70 kb, that is just telomeric of the TNF gene cluster (TNFA and LTA) and that is located between the microsatellites TNFa and C1-2-A. In this critical segment, four expressed genes have been thus far identified, NFKBIL1 (IkappaBL), ATP6G, BAT1, and MICB, all of which are candidate genes for determining susceptibility to RA. These results exclude the possibility of involvement of the TNFA genes (TNF-alpha) in the development of RA, which was suggested previously to be a strong candidate for RA in the class III region.

Alleles↗

PubMed2001

Lack of allelic exclusion and isotype switching in B cell chronic lymphocytic leukemia.

Two rearranged bands of the IgH gene were detected in a case with B cell chronic lymphocytic leukemia (B-CLL). The expressed VH gene was only VH1 with no somatic mutations in IgM and IgD. The expressions of C mu, C delta, and C gamma were detected by reverse transcription of RNA followed by the polymerase chain reaction (RT-PCR). Sequence analysis of the CDR3 regions of each PCR reaction product showed that the sequence of one rearranged allele was identical to those of the expressed VH1 gene, C mu and C delta, and the sequence of another rearranged allele was identical to that of C gamma. However, none of the expressed VH genes was detected in IgG. These findings suggest that this is a case of B-CLL lacking allelic exclusion and undergoing a class switch of one allele with the incomplete expression of the VH gene.

Aged↗

PubMed2001

Continuous long-term dosing with oral slow-release isosorbide dinitrate does not reduce incidence of cardiac events in patients with healed myocardial infarction.

BACKGROUND: In the short term, isosorbide dinitrate (ISDN) is considered to be therapeutically effective. The long-term effects of treatment with slow-release ISDN are less clear. HYPOTHESIS: The study was undertaken to investigate the effects of continuous, long-term dosing with oral slow-release ISDN on the incidence of cardiac events in patients with healed myocardial infarction (MI). The study was carried out in accordance with the intention-to-treat principle. METHODS: In all, 1.102 in- and outpatients, of either gender, with healed MI were randomly divided into groups treated with ISDN (n = 470) and not treated with ISDN (n = 632). Patients in the ISDN group received a continuous regimen of 20 mg of oral, long-acting ISDN three times a day, after meals. The mean observation period was 15.0 +/- 18.5 months. The primary endpoints were nonfatal and fatal recurrent MI, death from congestive heart failure, and sudden death. RESULTS: There were no significant differences in the baseline characteristics of the patients in the ISDN and no-treatment groups; nevertheless, significantly more patients in the ISDN group experienced cardiac events. In the ISDN group, 35 patients (7.4%) experienced cardiac events during the observation period, versus only 28 patients (4.4%) in the no-treatment group (p < 0.05; odds ratio 1.74; 95% confidence interval 1.04-2.90). CONCLUSION: Continuous long-term dosing with oral, slow-release ISDN does not reduce and probably increases the incidence of cardiac events among patients with healed MI.

Administration, Oral↗

PubMed2001

Relaxation behavior of laser-polarized (129)Xe gas: size dependency and wall effect of the T(1) relaxation time in glass and gelatin bulbs.

Size dependency of the relaxation time T(1) was measured for laser-polarized (129)Xe gas encapsulated in different sized cavities made by glass bulbs or gelatin capsules. The use of laser-polarized gas enhances the sensitivity a great deal, making it possible to measure the longer (129)Xe relaxation time in quite a short time. The size dependency is analyzed on the basis of the kinetic theory of gases and a relationship is derived in which the relaxation rate is connected with the square inverse of the diameter of the cavity. Such an analysis provides a novel parameter which denotes the wall effect on the relaxation rate when a gas molecule collides with the surface once in a second. The relaxation time of (129)Xe gas is also dependent on the material which forms the cavity. This dependency is large and the relaxation study using polarized (129)Xe gas is expected to offer important information about the state of the matter of the cavity wall.

Journal Article↗

PubMed2001

Acute myelogenous leukemia with PIG-A gene mutation evolved from aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome.

We report a patient with aplastic anemia (AA)-paroxysmal nocturnal hemoglobinuria (PNH) syndrome who developed acute myelogenous leukemia (AML). Flow cytometric analysis showed that the leukemic cells in the bone marrow lacked CD59 antigen on their surface and were positive for P-glycoprotein. Heteroduplex and single-strand conformation polymorphism analysis followed by sequencing of the leukemic cells in the bone marrow disclosed 1 frameshift-type mutation in exon 2 of the phosphatidylinositol glycan-class A (PIG-A) gene, which deductively produces truncated PIG-A protein. These findings provide direct evidence that the leukemic cells evolved from the affected PNH clone. Cytogenetic analysis in the bone marrow in each stage of AA-PNH, AML, and at relapse of AML showed normal, -7, and -7 plus -20, respectively, showing evidence of a clonal evolution. Because complete remission of AML was not achieved by intensive chemotherapies, allogeneic peripheral blood stem cell transplantation (PBSCT) from the patient's HLA-matched sister was performed successfully with recovery of CD59 antigen on bone marrow hematopoietic cells; however, leukemia relapsed 4 months after PBSCT. Leukemia derived from PNH may be resistant to intensive chemotherapy, and a highly myeloablative regimen may be required for stem cell transplantation to eradicate the PNH-derived leukemia clone.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Use of the fibreoptic stylet scope (Styletscope) reduces the hemodynamic response to intubation in normotensive and hypertensive patients.

PURPOSE: To compare hemodynamic changes after tracheal intubation when using a new fibreoptic stylet scope (Styletscope) and a conventional laryngoscope in normotensive and hypertensive patients. METHODS: Normotensive (N; n=30) and hypertensive (H; n=30) patients undergoing general anesthesia participated in this study. Each group was divided into two groups. In one group, patients were intubated by using a stylet scope with a laryngoscope as an adjuvant (S; n=15 each), while patients in the other group were intubated using a laryngoscope by the usual technique (L; n=15 each). The time necessary for intubation, hemodynamic changes, and adverse effects were recorded. RESULTS: Patients in the normotensive groups (SN and LN groups) showed significant increases in both systolic and diastolic blood pressures from before induction to one minute after intubation; however, blood pressures in the SN group were significantly lower than those in the LN group. Both systolic and diastolic blood pressures increased after intubation in the LH group, but not in the SH group. Heart rates in all four groups showed significant increases, and there were no differences between heart rates in the stylet scope and laryngoscope groups or between the normotensive and hypertensive groups. The number of patients who complained of sore throat was greater in the laryngoscope groups. CONCLUSIONS: Tracheal intubation with a stylet scope can attenuate hemodynamic changes and reduce the incidence of sore throat in comparison with the conventional laryngoscope technique in both normotensive and hypertensive patients.

Anesthesia, General↗