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Biomedical subjects

J Kaneko

Publications and source records attributed to J Kaneko.

At least 73 records · Page 4Linked to original sources
PubMed1997

Gene of LukF-PV-like component of Panton-Valentine leukocidin in Staphylococcus aureus P83 is linked with lukM.

Staphylococcus aureus P83 (ATCC 31890) produces five components, I to V for synergistic toxins, leukocidin and gamma-hemolysin [Sudo et al., Biosci. Biotech. Biochem., 56, 1786-1789 (1995)]. We report here the identification of component II, which is designated LukF-PV(P83) and its gene (lukF-PV(P83)). The lukF-PV(P83) gene was found to be one base downstream of the stop codon of the lukM gene. The deduced amino acid sequence of LukF-PV(P83) showed 78.4% identity with that of LukF-PV. The lukM and lukF-PV(P83) genes were encoded as one operon like that of Panton-Valentine leukocidin.

Amino Acid Sequence↗
PubMed1997

Sequential binding of Staphylococcal gamma-hemolysin to human erythrocytes and complex formation of the hemolysin on the cell surface.

Staphylococcal gamma-hemolysin consists of two protein components, F (or H gamma I) and H gamma II. To elucidate the mode of action of gamma-hemolysin, we studied the binding order of F and H gamma II to human erythrocytes and the cell-bound state of the two components. The binding of F to human erythrocytes preceded the binding of H gamma II to the cells, and thereafter hemolysis occurred. Western immunoblot analysis of the cell-bound gamma-hemolysin indicated that F and H gamma II components form high-molecular-mass (150-250 kDa) complexes on the erythrocytes. The toxin complexes were recovered in a Triton X-100-insoluble fraction of the erythrocytes, which contains cytoskeleton proteins. Neither the formation of the toxin complex(es) nor hemolysis occurred when the erythrocytes were treated with proteinase K. Abortion of the complex formation on the proteinase K-treated erythrocytes may be due to the failure of the binding of H gamma II to the cells, because F bound to the proteinase K-treated erythrocytes to the same extent as to the non-treated erythrocytes.

Amino Acid Sequence↗
PubMed1997

[Early establishment of bone marrow hypoplasia by antileukemic chemotherapy with concurrent rhG-CSF in a case of acute myelogenous leukemia complicated with intestinal perforation].

We report a case of 53-year-old man with acute myelogenous leukemia (M2) showing a karyotype of t(7;11) (p15;p15), del(10) (q11;q12), who was complicated with perforation of a duodenal ulcer during the antileukemic chemotherapy using behenoyl ara-C, daunorubicin, 6-mercaptopurine and prednisolone. As his bone marrow still showed high cell density and leukemic proliferation at the time of intestinal perforation, the therapeutic regimen was changed to a combination of behenoyl are-C and mitoxantrone, and daily rhG-CSF was concurrently administered for the purpose of early establishment of bone marrow hypoplasia. On the 8th day after the therapeutic regimen had been changed, his bone marrow became nearly aplastic, and complete remission was obtained on the 24th day. This case may indicate that the concurrent administration of cell-cycle specific antileukemic drugs and rhG-CSF is available for AML patients with emergent need of leukemic cell reduction.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Analysis of CAG trinucleotide expansion associated with Machado-Joseph disease.

There are currently some types of autosomal dominant cerebellar ataxias such as Machado-Joseph disease (MJD), spinocerebellar ataxia types 1-5 (SCA1-5), or hereditary dentatorubropallidoluysian atrophy. It is very important for these ataxias to be clinically differentiated, but that is sometimes difficult. In particular, the differential diagnosis between MJD and SCA1 is thought to be the most difficult. Recently, both MJD and SCA1 have been proven to be related to expansions of CAG trinucleotide in their causative genes. In this study, 20 cases of MJD in 13 unrelated Japanese families were genetically and clinically examined in comparison with 20 cases of age at onset- and duration-matched Japanese SCA1. The CAG repeat number of expanded MJD and SCA1 alleles was 72.2 +/- 3.1 (mean +/- SD, n = 20) and 47.3 +/- 4.4 (n = 20), respectively, and each repeat size was inversely correlated with age at onset in both MJD and SCA1. The repeat number in leukocytes increased from parents to children with acceleration of age at onset (anticipation) in MJD. In MJD, the number of CAG repeats in the expanded allele was lower in sperm than that of leukocytes, but was more in SCA1. However, the number of peaks in the expanded allele was greater in sperm than in leukocytes in both MJD and SCA1 (increased mosaicism level). MJD was clinically characterized by a relatively higher frequency of ocular signs such as eyelid retraction, bulging eyes, ophthalmoparesis, and nystagmus, spasticity in lower limbs, and sensory and urinary disturbances in contrast to the SCA1 patients except for slow eye movement. These results indicate that the expanded CAG repeat and clinical features are correlated in both MJD and SCA1, and MJD can be differentiated from SCA1 by clinical characteristics mentioned above as well as DNA analysis.

Adolescent↗
PubMed1995

Existence of a new protein component with the same function as the LukF component of leukocidin or gamma-hemolysin and its gene in Staphylococcus aureus P83.

Staphylococcal toxins, leukocidin and gamma-hemolysin, consist of two protein components, i.e. LukF and LukS for leukocodin and H gamma I and H gamma II for gamma-hemolysin. From a culture fluid of Staphylococcus aureus strain P83, a new protein component of leukocidin or gamma-hemolysin which was designated as LukM was isolated. This component showed the same biological activity as that of LukF component for leukocidin or H gamma I component of gamma-hemolysin in combination with LukS or H gamma II. However, the LukM component cross-reacted with the anti-LukS antibodies but not with the anti-LukF antibodies. On the basis of chemical analysis of the LukM component and the cloning and nucleotide sequencing of the lukM gene of S. aureus P83, we have demonstrated that LukM is an entirely new protein component of leukocidin or gamma-hemolysin. The deduced amino acid sequence of LukM from the lukM gene showed 66.7% and 67% identity to that of LukS and H gamma II, respectively. However, the amino acid sequence of LukM and LukF showed only 29% homology.

Amino Acid Sequence↗
PubMed1995

Traditional Chinese medicines improve the course of refractory leukemic lymphoblastic lymphoma and acute lymphocytic leukemia: two case reports.

A 34 year-old man with leukemic lymphoblastic lymphoma (LBL), who could not tolerate chemotherapy due to its side effects, was diagnosed to have an acute febrile disease by a traditional Chinese medical doctor, Lu Gan Fu. Zixuedan, a traditional Chinese remedy for dissipation of pathogenic heat and detoxification that could reduce WBC count including leukemic cells below 1000/microliters without intolerable side effects, was prescribed for treatment. A second case of acute lymphocytic leukemia (ALL) was a 41 year-old female who also could not tolerate chemotherapy. In her fourth recurrence, she started Chinese medicine including modified zixuedan, which gave her transient improvement followed by aggravation. Intake of previously ineffective cyclophosphamide in combination with Chinese medicine led to a dramatic improvement.

Adult↗
PubMed1995

Essential binding of LukF of staphylococcal gamma-hemolysin followed by the binding of H gamma II for the hemolysis of human erythrocytes.

Staphylococcal gamma-hemolysin consists of two protein components, LukF and H gamma II. This report clarifies the order of binding of the two components to human erythrocytes for the hemolytic activity of the toxin. The initial binding of LukF to the human erythrocytes is essential for the subsequent binding of H gamma II to the same cells, with the formation of a heat-undissociable protein of about 100 kDa containing LukF and H gamma II.

Bacterial Proteins↗
PubMed1995

Substitution of lysine for arginine in the N-terminal 217th amino acid residue of the H gamma II of Staphylococcal gamma-hemolysin lowers the activity of the toxin.

The staphylococcal toxin gamma-hemolysin consists of two protein components, LukF and H gamma II. Staphylococcus aureus P83 was found to have five components, LukF, LukF-PV, LukM, LukS, and H gamma II for leukocidin or gamma-hemolysin. H gamma II of S. aureus P83 was demonstrated to be a naturally-occurring analogous molecule of H gamma II [H gamma II(P83)], in which the 217th arginine residue was replaced by lysine. The H gamma II(P83) showed about 50% of the hemolytic activity of normal H gamma II in the presence of LukF.

Amino Acid Sequence↗
PubMed1995

Transfer to a nitrocellulose membrane allows of the bone forming activity of bone morphogenetic protein.

When we purify bone morphogenetic protein (BMP), its activity diminishes, and the quantity we are able to extract decreases. It is difficult to evaluate the effects of each of the processes involved in BMP purification because it is unstable. In order to resolve the problem, a modified bioassay method using only slight quantities of BMP which do not decrease its bone-forming activity, is needed. We transferred BMP separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) onto nitrocellulose membranes (NC) and cut out the bands. Then we used each band as implanted material. The NC membrane firmly bound the BMP activity fraction and held it in the implantation area of the mouse thigh. No formation of bone-like tissue was detected histologically at 14 days after the implantation, but, by 21 days after implantation, cartilage like tissue had clearly formed and newly formed bone was seen by 28 days. By implanting BMP transferred to individual NC membranes, we could perform a bioassay easily with small amounts of BMP without any reduction in activity.

Animals↗
PubMed1994

Inactivation of gamma-hemolysin H gamma II component by addition of monosialoganglioside GM1 to human erythrocyte.

The Staphylococcal toxins leukocidin and gamma-hemolysin consist of two protein components: F and S in leukocidin and H gamma I and H gamma II in gamma-hemolysin. The two toxins share one component (F = H gamma I). We found that the H gamma II component was completely inactivated by the addition of monosialoganglioside GM1 at the molar ratio of 1:1. Disialogangliosides GD1a and GD1b had little effect on the inactivation of H gamma II. The molar ratios of GD1a and GD1b to H gamma II needed for maximum inactivation were 30:1 and 100:1, respectively. Related glycolipids caused little if any inactivation. H gamma II bound to GM1 to form H gamma II-GM1 complexes. Analysis of the intrinsic aromatic amino acid fluorescence in H gamma II and H gamma II-GM1 with 280 nm as the excitation wavelength showed that GM1 in the complex reduced the fluorescence intensity of H gamma II by 12% without changing the wavelength of maximum emission (325 nm). We concluded that GM1 is a receptor of the H gamma II component on human erythrocytes and that H gamma II takes on a different conformation when it binds to GM1.

Amino Acid Sequence↗
PubMed1992

Purification and Properties of a Maltotetraose- and Maltotriose-Producing Amylase from Chloroflexus aurantiacus.

A maltotetraose- and maltotriose-producing amylase which is stable at alkaline pHs and high temperatures was detected in the culture filtrate of a strain of Chloroflexus aurantiacus J-10-F1, a thermophilic, green, photosynthetic bacterium. The enzyme was purified to homogeneity, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, by means of ultrafiltration, ammonium sulfate fractionation, and DEAE-cellulose, hydroxyapatite, and high-performance liquid chromatographies. The molecular mass of the purified enzyme was estimated to be about 210,000 Da. The isoelectric point of the enzyme was estimated to be 6.24 by polyacrylamide gel electrofocusing. The amylase was stable up to 55 degrees C and at alkaline pHs of up to 12.0. The optimum pH and temperature of the enzyme activity were 7.5 and 71 degrees C, respectively. Metal ions such as Hg, Zn, Cu, Mn, and Ni strongly inhibited the enzyme activity. The enzyme activity was reactivated specifically by Ca after the enzyme was treated with 1 mM EDTA. This enzyme could digest various kinds of raw-starch granules from corn, cassava, and potato. Both maltotetraose and maltotriose were formed as the main enzymatic products from soluble starch.

Journal Article↗
PubMed1991

Precision and reliability of stable microbubble test as a predictor of respiratory distress syndrome.

The precision and reliability of the stable microbubble test as a predictor of respiratory distress syndrome (RDS) were studied. In blind experiments, the stable microbubble test was performed by three analysts in quadruplicate on six different amniotic fluid samples obtained from pregnant women whose babies developed RDS and on three samples prepared from mature controls. Three-way analysis of variance revealed that there were statistically significant differential effects of the analyst, observer, and sampling on the stable microbubble values, and also that there were statistically significant interactions between the analyst and observer as well as between the analyst and sampling. However, the magnitude of these effects was not large enough to modify the interpretation of the test results. We conclude that the rapidity, simplicity and reliability of the stable microbubble test allow for its use as a bedside procedure in identifying infants who are likely to develop RDS.

Amniocentesis↗
PubMed1991

Purification and Properties of beta-1, 4-Xylanase from Aeromonas caviae W-61.

Aeromonas caviae W-61, which was isolated from water samples at the Faculty of Agriculture, Tohoku University, produced beta-1, 4-xylanase (1,4-beta-d-xylan xylanohydrolase; EC 3.2.1.8) extracellularly. The xylanase was purified to homogeneity by using DEAE-Sephadex A-50, CM-Sephadex C-50, and Sephadex G-100 column chromatographies. The molecular weight of the purified enzyme was estimated to be 22,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of the enzyme was 9.2. The optimal pH and temperature for the activity of the enzyme were 7.0 and 55 degrees C, respectively. The enzyme was stable at pH 7.0 at temperatures of up to 50 degrees C. As enzymatic products, various xylo-oligosaccharides such as xylobiose, xylotriose, xylotetraose, and xylopentaose were formed, and only a small amount of xylose was detected. The purified enzyme did not hydrolyze starch, cellulose, carboxymethylcellulose, or beta-1, 3-xylan.

Journal Article↗
PubMed1991

Purification and properties of two membrane alkaline phosphatases from Bacillus subtilis 168.

Two alkaline phosphatases were extracted from the membranes of Bacillus subtilis 168 stationary-phase cells and purified as homogeneous proteins by hydroxyapatite column chromatography. Alkaline phosphatases I and II differed in several properties such as subunit molecular weight, substrate specificity, thermostability, Km, pH stability, and peptide maps.

Alkaline Phosphatase↗
PubMed1991

Electron microscopic observation of recombinant Escherichia coli cells overproducing human tumor necrosis factor-alpha mutant as inclusion bodies.

Escherichia coli C600 r-m- carrying plasmid pTNF483 (E. coli [pTNF483]) produces a tumor necrosis factor-alpha (TNF-alpha) mutant protein in an insoluble form. A swollen region was observed in the SEM images to encircle the outside of most of the E. coli [pTNF483] cells just like a bandage. On the other hand, inclusion bodies of the TNF-alpha mutant as large as the short axis of the cell were observed in TEM images. This position was regarded as coinciding with the swollen region of SEM images. The inclusion bodies revealed in the swollen region of the cell envelopes were clearly observed in SEM images of isolated insoluble structures obtained by centrifugal sedimentation of a sonicated cell suspension.

Escherichia coli↗